He probably wouldn't, but it makes sense, in a weird sort of way.

Look at who's left here. We all get along reasonably well, even if we don't talk to each other every day. And we have been working together to find a way out of here. Maybe we're even getting close, and he's starting to panic.

Would any of you kill someone here just for the chance to escape? I think not. So the motive must have been crafted carefully, with the people left here in mind. While I don't think anyone here now would kill just to go home, especially not since we're figuring out more and more of this place as each week passes, I absolutely believe that many people here would kill to save the dead. Especially if they knew that 'death' here wasn't the end of things.