In his "non vixit" dream, Freud deals with his dead colleague, Joseph Paneth (1857-1890), who replaced Freud at the Vienna Physiological Institute. No wonder, Freud was incensed having lost his research position. And, no wonder, that he hated Paneth (aka P.).
As Freud revealed commenting on the dream book, he was, sacrificing to my ambition people [including P.] whom I greatly value. Now, taking into account that we have to do with a murderous mind, what does it mean that Freud was sacrificing people? Was Freud intending to kill anyone who was an obstacle in his quest for career, money, and fame?
As it is not uncommon among criminals,  Freud needed to share with the public the bizarre workings of his mind, but how could he reveal his murderous intentions without being identified as a murderer? Freud came up with a bright idea. He would write a dream book in which he would use fake dreams as a means of conveying his perverted and murderous message.
Thus, in a "dream", as Freud recounted, he annihilated P. As a result, P. was reduced to nothing.(1) As he revealed, Freud harboured a hostile train of ideas directed at P. Further, Freud mentioned, the premature death of my brilliant friend P., whose whole life had been devoted to science, Bizarrely, in Freud's lunatic mind, there was a convergence of a hostile and an affectionate current of feeling towards my friend P.
This was a common pattern in Freud's behaviour. He hated and wanted them dead, the very people he claimed he "loved" and admired.

Evil wish

As he explaineed, Freud annihilated P. because, as he claimed, P. was guilty of an evil wish. And, he made it clear that the "killing" of P. was akin to the murder of Caesar by Brutus (aka Freud). As Freud admitted, There was little basis in reality for my hostility to my friend P., who was very greatly my superior. Not true. It was P.'s superiority that was the very basis for Freud's hostility. Now, the obvious question is whether Freud did annihilate Paneth, and if so, when and how.(2)
As usual, when he is talking about "sensitive" content, to make the story hard to follow, Freud splits his narrative into two parts placed in different, distant places in his dream book.
Thus, in the second part, Freud continued elaborating on Paneth's path leading to the latter's death. As Freud claimed, his attitude was clearly expressed in the phrase, Get out of the way, so I can take your place. And, as he claimed, this very attitude toward their superior, professor Fleischl, was allegedly shared by Paneth.
Freud added that he, had had to reproach my friend Josef [P.] for an attitude of this same kind ... He had followed in my footsteps as demonstrator in Brucke’s laboratory.
No doubt, Freud wasn't happy when the professor told him to find himself a different career, P. instead taking his place. This was the basis for Freud's hostility towards Paneth.

Since Paneth was dead, Freud felt free to denigrate his former colleague, accusing him of wishing his superior, Fleischl, dead. Freud explained that, because Paneth could not expect to live long (Freud doesn't explain why), and since also this superior [Fleischl] was seriously ill, P.’s wish to have him out of the way might have an uglier meaning than the mere hope for the man's promotion. (In the original German version, Freud mentions the wish to ihn beseitigt, thus to eliminate him. The truth was that it was Freud, rather than Paneth, who wished to eliminate Fleischl.)
Thus, Freud claimed that Paneth wished Fleischl dead. Now comes Freud's confession. As Freud writes, a few years earlier, I myself had nourished a still livelier wish to fill a vacancy. And, a still livelier wish can be nothing else, but Freud's wish, plan even, to murder his superior, professor Fleischl. This is how Freud explained his motivation, Wherever there is rank and promotion the way lies open for wishes that call for suppression.(3)
And, when Freud talks about wishes that call for suppression, he means murder. This is how Freud explained his justification for P.'s annihilation,
As he [P.] could not wait for the removal of another man [his superior, Fleischl], he was himself removed. And Freud added, a part of the satisfaction I felt ... was to be interpreted: ‘A just punishment! It serves you right!’ Without a doubt, this statement confirms that Paneth didn't simply die of natural causes, but was annihilated by Freud.

And Freud callously - a psychopath's justification -  explained that, It’s quite true that no one’s irreplaceable. This statement was followed by Freud's bragging about his own "immortality",
How many people I’ve followed to the grave already!, he wrote. But I’m still alive. I’ve survived  them all; I’m left in possession of the field. [These [were] murderous, egoistic wishes.(4)] Freud wasn't bragging. Indeed, just as Freud recounted, people close to Freud were dying like flies.
And referring to Fleischl's death, Freud joyously exclaimed, I was delighted because I had once more survived someone, because it was he and not I who had died.(5)
As far as it is known, Paneth died of tuberculosis (6).  This is what, Wiener Vororte-Zeitung, of January 10, 1890, reported:
On January 4th at 10 a.m. the general practitioner and private lecturer in physiology Dr. Josef Paneth at the age of 33 died of pulmonary consumption he suffered from for many years. The deceased ... enjoyed great respect and popularity in medical and scientific circles.  ... May he rest in peace.
Since Paneth died allegedly of TB, Freud couldn't have killed him. On the other hand, if we believe Freud's hint that he killed Paneth, the obvious question is how it was possible.
And, there's one obvious possibility, Acting as the murderous Mr H Freud infected Paneth with TB, or some other deadly bacterium.
1) SE 5, p. 422.
(2) SE 5, p. 422.
(3) SE 5, p. 484.
(4) Appignanesi, Lisa & Forrester, John, Freud's women, (1992, p. 126).
(5) SE 5, p. 485.
(6) Jones, 1953, p. 166).

As it is apparent from his writings, murder was frequently on Freud's mind. Thus, in the Lecture IV,* pointing out the importance of slips of the pen, Freud recounted, the case of a murderer, H., who found the means of obtaining cultures of highly dangerous pathogenic organisms from scientific institutes by representing himself as a bacteriologist.
Now, it's an interesting question, who could this mysterious murderer by the name of H. have been. And if the case of H, was made public, why would Freud refrain from naming the murderer? Could it be because it was Freud himself hiding under the moniker, just like he was hiding under the guise of a patient in the Screen Memories where he was recounting, a likewise disguised, group rape of his niece, Pauline, perpetrated on her together with her brother, and his nephew, John?
So what was the purpose of obtaining those pathogenic organisms? He then used these cultures for the purpose of getting rid of his near connections. In other words, the culprit was killing people close to him, by infecting them with those organisms. And Freud brags that this was a murder, by this most modern of methods, which is consistent with pathological Freud's megalomania.
As a matter of course, only a doctor, like Freud, could get access to this kind of dangerous pathogenic organisms. As Freud explained - how would he know unless he himself was Mr. H? - on one occasion this man complained to the Directors of one of these institutes that the cultures that had been sent to him were ineffective.
Apparently, the first batch of the "organisms" didn't kill the intended victim. As Freud explained writing to one of the institutes, Freud revealed that, he [H.] made a slip of the pen, and instead of writing ‘in my experiments on mice or guinea-pigs he wrote quite clearly ‘in my experiments on men’.*
Now, this is a brazen confession in a disguise, but Freud always knew how to play with words in order to confuse the reader. Just contemplate what he is saying. He is talking about, my experiments, thus Freud's. And as if it wasn't enough for the readers to comprehend his meaning, Freud repeats the phrase. As a matter of course, unless he was H. himself, Freud would have no idea what the murderer wrote, and what kind of slip of the pen the murderer committed. Only the murderer, aka Freud, would have known those details.
* SE 15, p. 69.

And, the experiments on men, without doubt, refer to a murder by infecting the victim with the dangerous pathogenic organisms. As Freud explained that, the doctors at the institute were struck by the slip, but, so far as I know, drew no conclusions from it. How could Freud have known that, unless he was the murderer? The only possibility is that Freud was contacted by the institute, asking Dr Freud for a clarification.
Freud goads the reader, asking, Well, what do you think? Should not the doctors ... have taken the slip of the pen as a confession and started an investigation which would have put an early stop to the murderer’s activities? Apparently, they didn't, and thus the murderer aka Freud could, and did, go on killing. As Freud pointed out, a slip of the pen like this would certainly have seemed to me most suspicious; but something ... stands in the way of using it as a confession.
Here Freud starts playing the role of Sherlock Holmes, his favourite detective. As he explained, The slip was certainly a piece of circumstantial evidence; but it was not enough in itself to start an investigation. And Freud continued to elaborate on the issue stating that, the slip of the pen said that he was concerned with thoughts of infecting men, adding that it wasn't possible to know whether he had a clear intention to injure or ... a phantasy. And Freud clarified that the man, would have every subjective justification for denying the phantasy and would repudiate it as something entirely foreign to him.*
In other words, as a matter of course, even if contacted to explain his slip of the pen, the murderer would deny any intent of using it to harm people.  If one reads the statement attentively  it is clear that Freud was recounting thoughts of a killer. How would he know what the killer was thinking unless he was one?
Was Freud the murderous Mr H.? One can only admire Freud's method of hiding his crimes in the full view of the credulous public.
True, there's no smoking gun, but only a very stupid person would expect one! In fact, there's enough circumstantial clues to claim that it was Freud who, having obtained the dangerous pathological organisms, annihilated his "friend", Paneth.
* SE 15, pp. 69-70.

Both Freud's and Paneth's characters are apparent from their thoughts and actions. As Freud reported to his fiancé, on April 15, 1884, Paneth and his bride have invested in my name a capital sum ... to enable our marriage to take place six or even twelve months earlier. (1) Freud's gratitude for their generosity was a defamation of Paneth memory. (This wasn't the only occasion that Paneth supplied Freud with funds.)
In the same letter, Freud explained that, With this gesture Paneth is entitled to make a greater claim on my friendship ... and my only regret is that I seriously believe I won't be able to enjoy this new friendship very long.
This is a very odd statement to make. At the time, Paneth was in good health. Thus, it is a good question what Freud meant by this remark. Was he intimating that Paneth would die soon of natural causes - not likely - or was he explaining that he was contemplating helping Paneth to find his way to the other side? Lending money to Freud, that he wouldn't be able to repay, was always a risky business.
In the letter of April 1884, to his fiancé, commenting on the Paneth's generous donation, Freud showed his true feelings about his "friend" writing, Isn’t it splendid that a rich man should seek to ameliorate the injustice of our birth and the illegitimacy of his own favored position? (2) Without a doubt, Freud wasn't grateful for the donation ready to bite the hand that fed him.
Freud was a nasty piece of work.
He once went to a Jewish wedding, when his friend Paneth married Sophie Schwab. He gazed at the scene with a fascinated horror and then wrote a letter of sixteen pages describing all the odious detail in a spirit of malign mockery. (3) This is what Paneth's claim on Freud's friendship was like.
(1) Freud, S., Letters of Sigmund Freud, (1960, p. 103).
(2) Jones, (1953, p. 161).
(3) Jones, (1953, p. 140).