Originally Posted by
Often1
Easily. The gate reader scans the BP at each station and that adds pax to the manifest for the flight. If the BP isn't scanned in, OP won't be on the manifest and won't earn credit.
Bear in mind that this is a violation of the COC for the ticket and the t&c of MP (and other FF programs). If caught, the ticket will be refared and OP risks having his MP account closed. That's unlikely if only done once, but if he makes a fuss and that triggers a system audit to confirm that he boarded, it makes getting caught a certainty.
1. People do offload for various reasons, but are manually off-loaded from the system.
2. The GA and FA do separate counts which must match before the cabin door is closed because the numbers affect weight / balance. I have been on flights where something has gone wrong (or maybe somebody snuck past the GA on the way out) and they have held the aircraft while they hand match BP to manifest.
Rest assured, if you aren't on the aircraft, you won't get credit.