I did ask CS how this happened. We were told they had NO idea who had confirmed the request to book.
We had guests check out last Friday who were new to Airbnb, had no previous reviews and no photo. Although they respected house rules, left the place clean, etc., they did go home with two of our beach towels. I communicated with them about the missing towels, but got no response. After I put in a request for money to replace the stolen beach towels, I heard from them. It did end well, so there's that. Because they agreed to pay for them, I gave them a decent review.