ye, i only caught on the moment he got punched, but at that point it didn't matter if it was an actual betrayal or not, since the requirement was satisfied. it was just a matter of who gets to get their way first.
i feel like this is lowkey staged? the detective definitely had the chance to talk to baba and the old man earlier. i can't remember if baba actually tried to tell the detective that mc could kill in dreams, but if he did, all these happenings is a very good way to find out if baba was telling...