I didn't think his tone in the second email was level-headed at all. I thought it was a snarky reply to what was just a warning about the possible outcome.
That he would so boldly lie in the last email isn't level-headed at all, either. Nowhere in the first email did he say anything about him thinking it was a bad idea to disassemble it. The emails I've posted are the entire exchange we've had, except the phone call he made when he told me there was some wobble in the mount. He hadn't taken it apart at that point.
I'll see what the manufacturer has to say, and I'm holding a new one for him just in case, but I'd be surprised if the manufacturer offered to do anything more than fix any problem that existed and reassemble it properly.
I don't get upset with people who tell me the truth. It's the ones who lie and try to blame me or someone else for the problem who anger me.