[SPOILERS] I think Gene Hackman's decision was weird...
I think it was weird that Gene Hackman, who seems to be pretty keen on doing pretty good background checks of jurors, is willing to just pay some schmo he knows almost nothing about, who might very well be an anti-gun crusader for all he knows, $15 million.
If he really thought John Cusack was merely all about the money and was also trying to get money from Dustin Hoffman, wouldn't he think: "Hrmmm. I really can't afford to just pay that $15 million and just trust that John Cusack unless somehow I know for sure not only that Cusack has the persuasive ability he's tried to demonstrate for me but also that I know for sure that Dustin Hoffman is willing to pay. Because if neither of us pay Cusack, he could try to persuade the jury either way like any other juror could, and that'd be just like the situation I thought I was in to begin with. Perhaps I should instead just try to get the lawyer to suggest to the judge that John Cusack is threatening me and try to get him removed, and if that doesn't work, then just throw up my hands and hope it works out. I did spend a lot of time selecting the other jurors so hopefully I did that well enough to win this case. And if Dustin Hoffman does pay, perhaps I could investigate whether he did and use that as an issue for the appeal. But he probably won't pay because he'll be thinking the same thoughts I'm thinking right now. Not to mention that if it's ever found out that I did this, or that he did this, the one of us that paid the money could wind up in big trouble."
This whole movie depends on him not thinking that. So this whole movie seems kind of, y'know, defective, if you ask me. I enjoyed watching it though--probably this means I am dumb. But, this did bug me. While I was watching, I kind of thought maybe Hoffman and Hackman would get together and talk about the threats they'd received and figure out a way to get Cusack kicked off the jury and possibly thrown in jail, because I could not figure out how Cusack was going to really persuade either of them to get past the kind of thinking I was just talking about.