This HAS happened to me, but not for a CX reservation.

I was staying at a SHS and another person with the same first name and a similar (two letters transposed) last name was checked in with my res (and credit card!). The front desk spotted the error when I checked in and the look of panic on their faces told that they had screwed up big time. They never fixed it and I was billed for both stays. I ended up successfully disputing the other charge with Visa - so the hotel ended up having to pay a chargeback penalty.