Stupidity: Michael poses as an FBI agent to speak to Mrs Mahone including an ID badge. Mrs Malone is suspicious of Michael and why he is there. Yet she never examines the ID badge, something she would have done considering her ex husband is FBI and she would know a real one or fake one. (00:14:30)
And Then There Were 7 - S1-E11
Stupidity: When Michael realises they have too many clowns in the car, they think they can get rid of T-bag. But T-bag says he called someone and told them that "if he doesn't hear from me 5 minutes before the escape or 20 minutes after, he'll call the warden and blow the whistle." They could just go ahead as per usual until T-bag makes the 5 minutes before call, then kill him during the escape, and they still have 20 minutes after the escape.