Someone (hotel / guest) entered something wrongly and your record got pulled. And since the reservation showed information not yours other than the email address, then it was probably that which caused you to received the reservation. I suspect the actual HHonors DB records are fine as this is the first instance you had such an update. As for the Marriott, could have been promotions, etc If the real customer could do another dummy refundable booking, then you can know more but it is really not necessary.