No, no, no. You're saying the man gave you coins. It's gotta be the event where he comes up, says "Here you go, it's all yours" and disapears. THAT'S the box.
If you want your main to have the mask, choose the mask... If you want your main to have the clothes, choose the clothes... Why did you need to post? Choose what you want.
Wow, you're lucky! All drop-traders are stupid. If I were one, I'd atleast drop in a place where no-one goes, like Polnivneach or Miscellenia. We can't expect cheaters to be smart, though.
'Grats! Shame about the reward though, that's the worst reward the mime gives. I got my first and only mime when I was level 96 combat, and I got the mime mask.