Kneecap the ....... - then he'll be genuine in the use of his wheelchair.

I wouldn't have fallen for the original scam - my response would have been pretty much as suggested:

"Well, next time you'll get your arse to the airport on time - right?" or similar.

I'd rank queue-jumpers down there with beggars - I never fail to give those moochers a serve when the opportunity arises.

Or when I go looking for it...