or is it a glitch

It was strange for me that I had Michael looking like Max Payne throughout the entire game, and then close to the end his hair started showing up in cutscenes, and then it was back altogether. Something similar happened to Trevor. Franklins hair stayed braided though.

hair does grow back. i made trevor bald early on, then he slowly started getting more hair, (not his default hairstyle either, something in between that i haven't found at the barber shop) also noticed gastanks can be punctured and not ignited and you can actually run out of gas if you drive on them long enough.

I know the opposite can happen after having a transition of Michael shaving off the beard I cut into his face when I had the chance very early into the game.

@oldmanlight said:

what the fuck this is some metal gear solid type attention to detail here.

Ha, that's pretty damn incredible. I've never made any of the characters go bald, though. Mostly stuck to their default hair stylings for the most part, besides Trevor, whom has sported that handlebar stache pretty much across the whole game.

I noticed this too, my bald Trevor just disappeared

@bkbroiler said:

I would call "hair growing" some Deadly Premonition type attention to detail. Man, remember when the ER realized you could grow a beard? Good times.