The thing that gets me here is that he was already on the plane. I have no issue with them bumping people for valid operational reasons when they're not on the plane but he was on the plane. For a whole host of reasons he never should have been. They should have dealt with this before he got on.
But fine, you've got a full plane and now you have to bump people for operational reasons. Boy, it sucks to be you. I sympathize to the extent I'm capable of sympathizing with something bigger than a single person but you still have options here. The really obvious choice is start offering people cash. But I see the shareholders aren't really cool with that, fine, fine, I get it.
How about you make up some reason why everyone has to get off the plane? Does it suck more for you and everyone aboard? Yep. Is it way better than calling the cops and effectively beating him until he gets off the plane sparking national outrage? You betcha.
Next time don't fuck up in the first place or start giving cash.