All you could have done was report in-game after the incident. Trust trading is not against the in-game rules (not allowed to arrange them on the forums) however it is highly risky as you have figured out. I recommend removing the name from your post - or better yet, just remove the entire post because it will be hidden (naming & shaming) and nothing can be done on the forums. This is why trust trading is said to be 'done at one's own risk'.
Was doing a coordinate clue in the Lumby swamp and when I dug my spade into the ground I found my Zombie head, lol. Had no clue you could retrieve it that way.