Most of the coverage of the United Airlines bumping debacle assumes something like, "United Airlines had a right to remove that flier. But should it have?" But a close reading of the fine print of the contract included in every ticket purchased from United Continental Holdings strongly suggests that United in fact breached its contract with passenger David Dao.

The contract allows the airline to deny boarding involuntarily in case of overbooking. But that's not what happened; the airplane wasn't oversold. And Dao wasn't denied boarding. As far as we know, he was removed from a seat he had already taken after being assigned to it.

The contract's specific provisions for removing travelers or refusing to transport them don't include the airline's desire to free up seats, whether for its own employees, as in this case, or for other passengers.

What's especially interesting about this legal analysis is that it matches what I've always assumed was the airlines' norm.

Every frequent flyer knows that you might occasionally be involuntarily bumped from a flight before you've gotten on, because of overbooking or late check-in or another reason.

But I have long believed that, once you're on board, in the seat that's marked on your boarding pass, you're golden -- and can't be removed.

I say "long believed" because I have no idea how or when I came to hold that view.

I certainly never bothered to read the fine print of the airline contract or the federal regulations about bumping. The most accurate thing would be to say that my belief was based on widespread custom.