Ah, I guess that is one way to do it.
Bit of a palaver for a 2p giveaway though.

Thanks.
Seems the rule checkers are still limited by the steam API though.
One of the guys wouldn't have flagged anything because his DLC probably came from outside steam gifts.

Edit
Seems I could have spotted a different person who did get the DLC through here.
Guess older versions of steam gifts didn't stop you entering the same thing multiple times.
Definitely I see the previously won over the enter button for giveaways.

Edit2
Checked one that hadn't been viewed yet, and was able to unsend the key and request re-roll.
Looking at this guys list here on steamgifts he even gave away the bloody GOTY that has all the DLC.
Some people just want to win everything without bothering to check.