Scamming is scamming. I see you're trying to cover up your greed for pixels by claiming that you only did it for moral reasons because he is a scammer but that's just hilarious that you're trying to play that card and look like the good guy.
You could also say you just did it for the lulz, if anyone loses real respect for you because of scamming, then they aren't worth being friends with. For example I dont need any damn reason to, I dont trade anymore.