This is absolutely not what happened.
Here is the entire chat log on Steam:
http://pastebin.com/4Cpajhbf
I am only asking him to e-mail Humble support to see if they can help, as I made it very clear that I only wanted Sonic All-Stars Racing Transformed and owned the other games in the bundle already. I will absolutely replace the key if Humble denies the request, but dk_ refuses to even try and decides to air this out here instead? Well, alright I will simply buy a new key for him but I don't understand why he couldn't just try to contact support first before rushing off to smear my name.
And yeah, for anyone else curious, it does not appear that you can trade bundles between German/outside of Germany for Typing of the Dead/Sonic All-Stars Racing Transformed.