Flamestrike
Legend
My issue with it is mostly that show Joel had been more realistic until that point, killing so many armed people by himself seemed a bit much for him. In the game, you spend the whole time killing bandits, soldiers and infected by the dozens, so you're more used to it at that point.
It was heavily implied that he was not someone you mess with.
Like, Marlene, Robert and others who knew him (and were competent killers themselves, with literally an army of henchmen) were clearly terrified of him, and even to some extent Tommy (who'd explicitly seen him murder and torture people in the past).
I kind of got the Doc Holiday vibes from Pedros performance at the end. He was a man who didnt care if he lived or died, which made him much more dangerous in a gun fight.
I do agree though. He seemed to suddenly manifest hardcore military CQB skills from somewhere, and we all know he never served any time in the Army (unlike Tommy).