Originally Posted by GUWonder

If this happens in RGN or wherever, you'll likely have visa stamps or other documentary evidence of having been in the vicinity at around the time of denied check-in/boarding. I don't see any reason why an airline employee would want to lie under oath to an officer of the court on behalf of their employer -- it would be an invitation for personal problems for the airline employee who would be abandoned by their employer. More likely the airline employee or the airline's rep could just innocently claim that did they not have any record of you being there.