i actually watched quite a lot of videos of people burning. it's pretty common trend for people to just stand there like zombies not doing too much. you'd think they would scream and run around but actually no. it has to be some kind of shock for organism or the brain and hot phumes cooking the fucking brain up, or maybe just the pain that makes you act like that.  animals do it too, i've seen videos of gazellas or zebras getting their guts ripped up or their face fucking ripped off and they just casually walk around till they just drop and die. adrenaline and shock is a weird weird combination.
Poland