User blog comment:The Milkman/The Writing of the Ending/@comment-5144441-20120601071637/@comment-4237253-20120604094712

I think what matters most is that it is entirely out of character. Joke wouldn't betray his friends suddenly because he is afraid of dying. He's smart enough to know that if they don't win this fight, they'll all die later anyway.

Also, for it to be a relay jump, he would have to travel from Earth to Pluto.