3 reviews he has...ok then, buy a few product, leave bad reviews, the business will never get any sales after that...
If you are caught then you will lose your account though, so be careful
anyone can copy you anyway, this drunk guy or a random person anyway........
You should have cushioned him until you get that non-disclosure agreement signed. File a copyright infringement claim with Amazon and his listings will be taken down. Hell, nowadays anyone can take listings down by claiming copyright...etc
I'll give that a shot, for starters, and see how far that goes....