Other mistake: Virtually all the text in the various articles and reports in this movie are fake. Look at the John Kramer article at the very beginning, even at first glance you can tell it's an article about pilgrims or something and has nothing to do with John Kramer. Also, when Staham is going through the articles he found on Hoffman's sister, you can very plainly see that every article (there are a few) is just the same typed out story copied and pasted into various formats. (This doesn't even require slow motion, just pay attention.) (00:11:45)
Other mistake: When Agent Strahm first starts investigating, he uses the FBI computer to look up Seth's name. He is heard typing many more characters, very quickly, than actually show up in the 'search' field on the screen. (00:29:20)
Other mistake: Seth is told that in 30 seconds the pendulum will drop low enough to cut his body and in 60 seconds it will cut him in half. We then see the clock start ticking. After Seth has crushed his hands, we see the clock - 46 seconds have passed and yet the pendulum hasn't cut him yet. (00:04:35)
Answer: That was the entire point of the trap. Each trap in the overall game was meant for them to all work together. The tape for this trap asks "Who will be the odd man out?" They took this to mean that one person had to remain outside the chambers, but what it really meant was two people would each share a chamber (assuming all five survived the first trap) and one person would occupy the third chamber all by themselves. Charles realised this and tried to tell everyone, but was unfortunately killed by the explosion before he could.
Phaneron ★
Nope actually he said who of you 4 has to die...how he knew was 4 survivors?
He does not say that at all. The exact wording is "With only three points of safety, which of you will be the odd man out?" At no point does the tape say that one of them has to die. That would be completely contradictory to the point that the five of them were supposed to work together to safely get through every trap.
Phaneron ★
Not what he meant. He knows human nature is survival at the expense of someone else. He set the trap so all could survive, but he knows the panic and self-preservation will lead the group to sacrifice someone.
The_Iceman