I would guess it's not the dystopian fascist state he has a problem with, having grown up in it and rose in the ranks of the group that keeps that state in power, but the shooting of unarmed citizens, which this must've been the first time he himself was ordered to do so. We know they suppress all news so it wouldn't be out of the question that Ben didn't know the murder of unarmed civilians was something that happened.

I took a look at The Running Man's TV Tropes but nothing jumped out at me as what you're looking for.