Verified purchase review not linked to order

We have a negative verified purchase review submitted 08/12 stating the product broke 2 months after purchase, ASIN B0CF2W6DQ9. I wanted to offer the customer a replacement part, at no charge of course, or even a refund if it was not able to be corrected. We have no record of this customer ordering from us, and when I go to offer a courtesy refund the canned email message created by Amazon has the order information redacted. I looked at every order going back to January, and none of the orders had records of reviews in the order back-end. I am scared to go through with the courtesy refund now without being able to actually verify the order; I don't want Amazon to automatically refund the customer if I offer it and I'm never able to verify it. The only other review is a 5 star and even it is not in the back-end order info as being reviewed, but he definitely ordered from us, so I can verify that one.

Are reviews actually verified by Amazon? How? Why are the reviews not linking to their orders? Is there any other way to actually verify the negative purchase before offering a refund?