how could a man know he'd been SA'd?

TW: drugs, alcohol im not a victim, i just want to understand

i just heard this story from a man, let's call him jake, close to me.

he was on vacation with a friend, got very high and drunk at a bar (all legal). they met a mixed group of people they got on well with and invited them back to their hotel. they had two hotel rooms but were partying in one. jake barely remembers any of this. he remembers there was a girl in the group talking to him and that he had to be basically carried back to the hotel. he was told by his friend he was totally out of it and there are videos of him laying on the bed and on the floor almost unresponsive. the next morning he woke up in the other hotel room with the girl he was talking to. he was naked, he couldn't see if she was naked too but he left the room immediately and then asked his friend to leave the hotel as he was extremely confused and shocked by the woman next to him. his friend just said he doesn't really recall how he made it to the other room, but that the woman definitely wasn't as drunk/high as he was.

ha says he feels really weird about what happened, he doesn't know if in the moment he wanted to have sex (if they even did, he was too ashamed to ask the woman), but he does not recall wanting to have any relations with her in the parts of the night he remembers.

i told him if any female friend had told me this i'd definitely tell them they were probably SA'd. he agrees but says since he's a man he doesn't feel like that woman could've done any harm to him and he probably wanted it in the moment.

i feel so conflicted, what are your thoughts?

edit: he also messaged the woman asking how she ended up in the room with him and she claims he invited her, and also said she liked him and that he was really fun drunk