Was that the point where House handed the gun back? Because anyone who didn't see that coming doesn't understand House. He made a deal with the patient -- hand over the gun, and he would do the X-Ray. House handing back the gun was, in my opinion, a matter of honor and the honorable thing to do.
I'm not sure that it was a point of honor. House is more the type who'd hand back the gun so that the threat persisted, thereby keeping the SWAT team out as long as possible. That way House would have more time to solve the mystery. If House kept the gun, the SWAT can come right in because there are no longer hostages they have to be careful for.