Question

Nothing, but if he wins it ll give a reroll.

He won't be "kicked" from the giveaway, the only way he could leave it is if he leaves it himself, then he wouldn't be able to rejoin

EDIT: However, as makromate said, some people wouldn't be happy about giving him the game. I personally wouldn't mind, as long has his CV dropped because of a price drop in the store, not because of him trying to exploit CV