I think the heat made them all just a little crazy esp with no sun block
and i don't remember much of the movie ... maybe cause 80% of it was just flogging and killing etc.
but i have a hard time thinking of it as like a majority of the jewish people in that time being purposefully malicious. but if maybe say they were just the poor jews and promised food ... or some sort of motivation, i could definately see that. hunger makes you do crazy things >.<