Proposal: in the logged comment added to the history in the Pending change review process, for accepted revisions that have no "accept" comment by the reviewer, unlink the word "accepted" and make it plaintext. For accepted revisions that have an "accept" comment, link the word "Accepted" to the log item that contains the reviewer's comment.

Alternative UX: To make it more obvious when there is or isn't an accept comment, add another token ('why', 'reason', 'log', or some such) to the acceptance tag, and link that, instead. Thus, no-comment acceptances would have three words ([accepted by Username]), and commented acceptances would have four: ([accepted by Username ([log-hyperlink|reason)]).

Detailed rationale, and real-world examples at this discussion at Wikipedia talk:Pending changes.

(Sorry, still trying to figure out how to find a project or tags...)