Three dollars and some change

All Christoff is obligated to do is protect *Harry*. Even if that involves knocking him out and dragging him away from the battlefield in London.

I was going to ask another question or two based on your reply to my comment, but you've answered it here. Obviously I wasn't thinking this through enough, because you're right - the simplest, most effective way to keep Harry safe is to remove him from harm's way. I doubt Harry (or Anita, Dumbledore, etc, etc) would be particularly happy with that solution, but it would certainly be effective.

Of course, this still has huge potential to blow up on Christoff if Voldemort feels that playtime isn't over for Harry, especially since Christoff couldn't expect much in the way of reinforcements from pretty much anyone.

Poor Christoff. Ah well, at least he's had a learning experience from this - don't make binding commitments while drunk. It's probably just as well that he's not the master of Las Vegas.