No.
I don't agree with BigAndy69, no offense, but I think you are being way to hard on yourself. First of all, I wouldn't pay some one else to get, I actually go to Mexico allot by myself for this reason, secondly, if I were to but from someone, they'd have to convince me it was a good risk, or have the gear so I can inspect it first.
But in your case, this guy paid you, you both got scammed, my view, talk to that friend of a friend once more, explain that the money was sent, and you both got ripped off. That's the risk.
Same with pot or anything else. I mean if it had been confiscated by customs / feds he wouldn't be so eager to claim it I'm sure.
Tell him you are sorry for his loss, but to look at you, your not huge, and therefor not on gear ( for the last YEAR ), so obviously your not lying. And if he still can't accept the fact that his loss was just as much his fault as yours for going through a friend of a friend instead of doing the research and scoring it for himself, I mean, it doesn't take a rocket scientist.
No matter what, don't give him a penny, fight it out if you have to, but don't pay for his own dumb fucking asses mistakes.
Peace.