 What caused Ben to physically assault Cobb?
With never a moment to rest, the pursuit through space felt like a game of hounds and hares ... or was it follow the leader? Ben Curtis eased his pale, gaunt body through the open doorway of the Blast Inn, the dead man following silently behind him. Again, its face would be a pop-eyed mask of surprise as Ben's fist thudded into its jaw. It had begun a week ago in Luna City. Cobb was persistent: "Damn fools shoulda known enough to stay on Earth. Ben rose and started to leave the bar, but Cobb grabbed his arm and held him there. Until this instant, Ben had suppressed his anger. Under interplanetary law, that would mean ten years in prison and a dishonorable discharge.
 Cobb's vocal disgust for spacemen.
 Cobb physically assaulted Ben first.  Cobb's vocal disgust for spacemen.  Ben was trying to prove a point about his masculinity.  He thought he was someone else.