What's the best way to fix a "Not Received" due to a winner's non-working e-mail?

Last month I (stupidly) decided to try giving one of my giveaway winners his game as a Humble gift, following Humble's partial gifting FAQ and entering the e-mail address of the winner at the gift URL directly.

Unfortunately, the winner claims that he didn't get the e-mail from Humble, and he also doesn't respond to an e-mail I sent him myself, so it appears that the address he provided is wrong or unreliable (he did say in the GA comments that he'd checked his spam, etc, but didn't respond to my request there to check his supplied e-mail address).

The Humble gift URL apparently only works once, so I contacted Humble's "ninjas" asking them if there was a way to re-send to a working address (if I get one) or to let me get the key myself (so I can add it on the SteamGifts winner page), but I've had no response from them after five weeks (I also asked if they could confirm that the key hadn't actually been claimed).

This is currently the only "Not Received" on my otherwise perfect record, so it irks me! I also notice that the giveaway winner is currently suspended.

I'd ask for a re-roll, but I don't want to disappoint the new winner and risk my track record if the key was actually claimed. What other possible actions can I ask SteamGifts support to take to resolve this?

From now on I'll stick to just getting the key myself and providing it directly via SteamGifts...

EDIT: Thanks to Mullins for his suggestion; support agreed to delete the giveaway and my perfect record is restored!