Yeah, I don't know the answer to your question, but I'm still pretty sure the joke of the meme is what I explained. So the time traveler wonders if he came before or after someone's death, but then the man he approached on the straat says it's before that person's death. Now he couldn't possibly know that this "someone" would die in exactly three days, of couse, so this indicates that he planned it all and is in fact the murderer.
