It's not Ben's fault. Everything that went wrong in Episode 3 is Lilly's fault.
Ben actually saved everyone's lives by giving tribute to the bandits. While talking the leader down in the confrontation you can actually get him interested in setting up a more official tribute relationship... the bandits don't fully attack until Lilly shoots. All Ben did was do it behind your back, but his supplies were the only thing keeping the bandits from killing everyone. He obviously didn't tell anyone because he was afraid and everyone except Carley (and Lee, depending on how you play) treats him like shit so he doesn't ever talk about it. The bandits already knew where the motor inn was and would have massacred everyone if it weren't for Ben.
Lilly was the only was who noticed supplies missing. When you ask everyone about it they show more concern for Lilly's mental state than they do for the missing supplies. Even Lee himself states he doesn't notice the missing supplies. If he hadn't removed the stash after investigating on Lilly's behalf then the bandits wouldn't have attacked. It's because Lilly refuses to leave the motor inn that the bandits are even in a position to attack your group.
I know a lot of people hate Ben but he doesn't deserve it... he did was he thought was right and it was, even if it was duplicitous.