I'd say that his vice is being ostentatiously grouchy so that he can push people away. Doesn't work at all with his team, not anymore, but he keeps at it. It's a habit of sort, and a way that he protects himself.

That's interesting, that's so close to how Bradygirl above you described Bruce's vice! :D It's a really fun flaw for a character to have, honestly....

That SF novel sounds like a blast! I hope it goes great!