Breaking the rules

Well, you can't be sure, but for example I bought the bundle BTA, but the Scribblenauts you see in my profile isn't from my bundle. I'm saving that game for a friend, so another person gave me his leftover key. I could have won the game here too and there wouldn't be anything wrong with it. I've given away Rayman Origins here three times before getting it for myself too, and I entered giveaways for it in the meantime.

if he didn't activate his key then he is not breaking any rules. And for reporting - look at the top of the page - see the Support link next to a Forum? click it :>

If the dlc is not activated on his account at the time he won the giveaway, and still isn't, you don't have an 'official' reason to not giving it to him...