Behold, a Distant Star - S2-E10
Stupidity: When Johnny finds out his father is alive and wanted for murder, he is livid with his sister for telling him neither fact. When Sue decides to tell him the whole story, she asks Reed to pull a photo album from the drawer next to him, which contains a newspaper clipping detailing that their father was wanted for murder. If Sue didn't want Johnny to know about that, she shouldn't have placed the clipping in a photo album, and then kept the photo album in a communal area where Johnny could have easily discovered it at any time. (00:06:19 - 00:07:34)
The Origin of the Fantastic Four: Part 2 - S1-E2
Stupidity: The Puppet Master has Sue chained to a chair, but he keeps the key to her chains on a desk in the same room while he is preoccupied in the next room, giving her an easy opportunity to escape. (00:09:08)
Suggested correction: And yet he later states that he was prepared for her escape attempt.
Moreover, when she tried to escape, he wasn't surprised by this at all, indicating that he expected this to happen.
The Origin of the Fantastic Four: Part 2 - S1-E2
Stupidity: When the robot is engaging Thing and Johnny, they both just stand there and let the robot attack them. This is especially dumb on Johnny's part, because he witnessed the robot knock Thing across the room before it turned its attention to him. (00:10:55)
The Origin of the Fantastic Four: Part 2 - S1-E2
Stupidity: When the prisoners in the cell block have all been released from their cells, there is news footage of them running around freely through the cell block. This is a foolish thing for the news crew to film, as they could easily be taken hostage by the prisoners. (00:08:52)
The Origin of the Fantastic Four: Part 2 - S1-E2
Stupidity: After Slash takes the guard's gun, he begins to wildly fire it into the air, all the while the news reporter remains on the ramparts giving an interview to the prison warden, even though either of them could easily be hit by gunfire.