Or you will be noted as no showing your flight, which AC cancels your ticket and you would be forced to buy a new one. This would be the best way to stop game players.
Unlikely in the OP's case. Was initially told by an FA he was on a 6:30 flight, told at 4:10 he was actually on the 4:30 flight and still had to clear security and immigration? It's well below the MCT. Missing that flight isn't game playing and not grounds to cancel a flight on a no-show basis.