Can you only run into the homeless guy once?
Edit: NVM, he's just very rare. Sheesh.
There's at least a second event with him, but tbh events in general seem to be so rare that you won't get many through your playthrough.
I don't know if they're tied to certien days or osmething, but even freezing the day-count so I can play 300 days didn't let me see all of them.
Plus, there's a tendency for stuff to trigger early before you have the stats to actually use it.
In my first (non-cheating) playthrough I got the robbery event (x2), the homeless guy and the groped-on-a-train event, but literally the only option I had for all of them was to just pass the event by because she wasn't slutty enough to do anything.
(With the second robbery event I managed to get his gun because i'd been training my speed.
I thought it would be useful for some kind of combat that i assumed would be coming later in the game, but nothing ever did. At least speed is useful for hunting, unlike intelligence and charisma which seem worthless.)
I hadn't had Vesper masterbate enough, so she wasn't slutty enough to do anything in any of the other events.