[Kaitel]

Dexter couldn't win, if he had stuck with the unknown unspoken plan, which he never agreed to in the first place, then Charlie would be out and his haters would say why did you not give her a chance of picking higher when you knew she wanted to stay. He went in talking about 4's and 8's saying he was gonna choose either 4400 or 8800, that's why he picked 8800. He had no way of knowing for certain what everyone else would pick. Sam grabbed the 100k with no thoughts of the others safety, that's more selfish IMO.
Sam was just annoyed Dexter was safe and Callum's brainwash kicked in to overdrive again, and the twins were just hypocrites cause they didn't choose the next highest either anyway.