Stupidity: On 9/12/05, during Eve's trial, her sister Liz stood up in the courtroom and began a diatribe in which she discussed subject matter relevant to the trial. Ethan then told Eve that this had harmed her chances. Why, then, didn't Ethan ask for a mistrial? A prolonged outburst like that is a classic example of something that would precipitate a mistrial.
Turkey Guys - S13-E5
Stupidity: The whole episode revolves on the turkey that Peter ate. Lois sends him and Brian out to get another one. She stalls dinner the whole episode waiting for them to get back. Problem is the turkey is frozen! It will take at least 6 or 7 hours to cook and Lois acts like as soon as they return with it, it won't take long to to cook, so the stalling makes no sense. (00:12:45)
Stupidity: Paulie and an associate just killed 2 drug dealers or stash house guards, and they are rummaging throughout the apartment touching appliances and other surfaces without any gloves. Paulie was previously arrested and did time so his fingerprints are on file. Paulie also used a knife to stab one of the Colombians without any gloves on, and he just left it in his body. The police would have no problem linking him to this crime within a week after forensics did their sweep. (00:03:00 - 00:04:17)