Dr. Nathan Waldman
was Waldman a good guy or bad guy? it seemed like he was a good guy, he seemed to be trying to help them. I like the character, I like it when Brian Cox plays likable characters, he's a good actor. I enjoyed his scenes, funny as hell.
edit: after re-watching the movie I answered my own question, he was a good guy, I guess I missed part of the last scene he was in, I remember the part where they think he was crossing them, but when he catches up to them, you find out he is a good guy.
Sheriff Joe came to Arizona to chew bubblegum and kick ass... and he's all out of bubblegum