A guy sold me an HP calculator, advertised as "in perfect condition" while in fact keys on it were broken, it was badly warped, and cigarette ashes were falling

A guy sold me an HP calculator, advertised as "in perfect condition" while in fact keys on it were broken, it was badly warped, and cigarette ashes were falling out of it. I gave him negative feedback and he went ballistic, saying "You should have sent me a message privately, rather than give me bad feedback! I've been on eBay for ten years with no bad feedback. I would have made it up to you." I explained that his kind of behavior was exactly what bad feedback was for. eBay feedback is badly broken if people aren't supposed to actually use it.