There was an issue with the key he gave me but gave me my csgo keys back right away.
I gave him a key for Spec Ops: The Line in exchange for his key for Savage Resurrection.
What he didn't tell me was that it was some beta key that was about to be revoked, which it was a few days later. So something fishy it was that he was doing. I have contacted him for an explanation but he has blocked all contact. Strange that the first ever to cheat me was an level 49 american profile. Had never thought that.
Here is the converstion foregoing the trade.