'Bumping' is the colloquial term for 'involuntary denied boarding'. Bumping does not apply in this case, because the passenger in question was already boarded, and therefore could not be denied his seat, as he was not acting abusively.

But don't take my word for it, this is directly from the US Department of Transportation:

> Can airlines involuntarily bump me after I have boarded the flight?

> Generally, no. If you have met the following conditions, airlines are not allowed to deny you permission to board, or remove you from the flight if you have already boarded the flight: > You have checked-in for your flight before the check-in deadline set by the airlines; and > A gate agent has accepted your paper boarding pass or electronically scanned your boarding pass and let you know that you may proceed to board. > However, airlines may deny boarding or remove you from a flight even after accepting your boarding pass and informing you that you may proceed to board if the denial or removal is due to a safety, security, or health risk, or due to a behavior that is considered obscene, disruptive, or otherwise unlawful.

https://www.transportation.gov/individuals/aviation-consumer...