Append HTML to review markup

Scenario: Users can review John’s product or Andrew’s product. If John is logged in the wordpress admin (limited capabilities) and is browsing the frontend, reviews of John’s product will show a ‘reply’ link underneath which John can click. (Rather than John being able to view/edit all reviews).

I am hoping to add a ‘Reply’ link under reviews that are associated with a particular user and that user is logged in. To do this, I would need to append some code to a review.

I don’t suppose there is a hook that I am missing where I could do this? I know it’s a rather bespoke scenario.