Well you’re not touching your face when you’re passed out.
Unless that’s where your hand lands.
That's a fool's reassurance if you're binging with friends. If you can get it from someone's respiratory droplets surely you can get from their vomit. There is an example of this from the literature in the 90's.
Marty: What happened to Stumpy Joe?
Derek: Well, uh, it's not a very pleasant story...but, uh, he died...uh...he choked on...the ac- the official explanation was he choked on vomit.
David: He passed away.
Nigel: It was actually, was actually someone else's vomit. It's not....
David: It's ugly.
Nigel: You know. There's no real....
Derek: You know they can't prove whose vomit it was...they don't have the facilities at Scotland Yard....
David: You can't print, there's no way to print a spectra-photograph...
Nigel: You can't really dust for vomit.