Some years ago Air Canada ran a similar style of promotion. They counted down in front of the press, and when the lucky millionth passenger was pointed to at the gate - they turned out to be an employee of Canadian Pacific Airlines. Maybe even travelling non-rev.
And there was some stick in the press, and I believe the
PR director got the sack for it.
So don't think these things are not set up beforehand (of course you knew that). I always remember the first ever arrival at Heathrow T4 the day it opened. TV cameras all there, Lord (King or Marshall?) ready to give an award to the first pax to use the terminal, and out from an overnight flight from the Far East steps a (OK, expectedly First Class, they are first off) pax all nice and shaved and neat in his suit ready to shake My Lord's hand. From an overnight flight from Asia. Ha ha !!