Day 4: 11:00 P.M.-12:00 A.M. - S4-E17
Stupidity: When the couple is in the plant they call Jack on the cellphone, he instructs them to open the case and separate the book from the activation device. This was stupid, he should have told them to destroy it, since the codes had changed the moment Air Force One crashed, and it would take about 1 hour to make this work. This is explained later on in the show.
Stupidity: Lance and Lana's actions at the end don't make sense, other than to set up conflict for the plot. Lance won't give Lana a shot. Lana steals a vile and after Lance injects Lex (to stop him, fine), he finds Lana, who is trying to inject herself. He stops her, throws her back, then proceeds to try and inject her. He could have just waited and let her do it herself, or taken the vile and left. Lana is then scared that Lance is about to inject her when that's what she wanted in the first place.