[masraum]

I don't have any advice. I do like some of the ideas about a calm response, but at the same time, I also see a great point behind not having ANY interaction with a nutjob. He's obviously one of those folks that are off, and you never know what's going to set them off.

In this case, the safer option may be to not respond, especially if your one other employee is ever their alone (I assume that's the case).

Good luck. I suspect his review won't hurt your business in any measurable way.