To clarify, they're author of the resource, not the review itself. I'm guessing the logic to show the field is checking if they're author of the resource, rather than author of the review.
Thank you for reporting this issue, it has now been resolved. We are aiming to include any changes that have been made in a future XFRM release (2.1.7).
Change log:
Show the alert field when the author is deleting resource reviews on their own resources