I guess I'm the odd man out here. If the player claims the stick is game used I (as the card company or collector) am going to take him at his word.
Unless there is a database of stick serial numbers, and a way to confirm they were actually on the ice during a game (NFC chips?), there's no way to prove otherwise.
Hockey & Baseball cards: http://www.checkoutmycards.com/Users/Riverdome