I don't think I can add anything at the moment. I'm going to need to think on this, and maybe re-read the chapter.
One thing, if Eric was smart, he would have left a voice recorder where the guys couldn't see it when he went for his swim. He would have expected the guys to talk, and they might have let slip something useful to him. Indeed, they did -- the fact that Dex has the real datastick.
Also, if he was smart, he wouldn't be assuming he was given the right password. If they die, and he believes they are the only ones with the right password, then he loses. He shouldn't let them die until AFTER he has confirmed he can decrypt that data. If that's the case, I'm expecting him back in the near future to tell them that the password was wrong (I'm assuming he will use a cellphone to give the password to the Thaddeus, who will then confirm that he has the wrong password). Of course, he's blown it by telling the guys that he can't let them live, so why should they give him the password in the first place?