A friend was flying thru ATL today. Her original flight was oversold, so she volunteered. In the end, there were seats available so she took her original flight.

When it was time to board the connection in ATL, her seat was gone. The assumption is that the GA for the original flight somehow messed up the connection. Should she be getting anything for the mistake? If so, would it be VDB compensation, IDB compensation, some meal vouchers and a later flight?