I noticed that myself too and I was a bit weary myself however the guy actually refunded me twice. 1st reason was because his 2 factor authenticity for his coinbase wallet wasn't available, his mobile fone wasn't with him. And lastly only a couple of hours ago refunded me because he was in a rush to get to work. I can't label that a scammer, as he didn't actually run off with the funds but the transaction never happened if that clarifies your concerns..