The event on day 10 doesn't happen on sals route. I mean you do fall asleep directly on top of him kind of hard for him to do anything in that position. He can't get up without waking you up and since he's not alone no one can get to him to suggest whatever it was that caused the event.
I think that’s the case. Since his issues are “solved” with you being there, anything that happens with Sal in his route is always possible to deviate from the norm, like him actually seeing you pass out in the vault. Sleeping with him prevents his sleepwalking, so any event caused by sleepwalking is kinda cancelled by you