That would hurt.
I read some where or other that this round had passed through some other barrier before hitting him. Either way it is not unheard of for all manner of pistol rounds to impact a human head and not get the desired result. Movies and video games and just what seems like common knowledge makes most people assume that any shot to the head is a show stopper. It’s not always. Now how much fight this guy would have had in him after taking that round is anyone’s guess. The level of anger, booze, drugs or desperation would determine if he still carried on the fight assuming it didn’t knock him out.
As we have all heard a million times, shoot them until they know they are dead.