Agreed. The seller here thinks he can scrounge up some legal recourse because Amazon "told him" he can't make single use codes. The correct action in this case

Agreed. The seller here thinks he can scrounge up some legal recourse because Amazon "told him" he can't make single use codes. The correct action in this case is to just abandon the coupon code thing entirely, not to make an unlimited code and ask the buyer not to share it.