Again, that is based upon an assumption and no solid facts. If a game is free somewhere, it can be assumed that some users posted them to SteamGifts from there posted them, but it doesn't automatically make every time that game is posted to SteamGifts, people got from that link.

Also, I'm pretty sure by free games, they mean games priced free, because if we apply that idea of free keys given to you can never be used, then that means technically developers giving users keys to give away on Steam Gifts will have to have the user reported, doesn't sound right does it? Whereas if we look at the submit a new giveaway button, no free games on Steam show up, because again, SteamGifts listed it out and don't accept them.