There is a good explanation of the edit process here: http://meta.stackexchange.com/questions/76251/how-do-suggested-edits-work

It appears that in this case, when the response was "Reject and Edit", that was recorded as a rejection by Community, and then the edit by the user that made the review.

Since the original edit does not appear in the revision history, it appears that the reviewer marked the original edit as "not helpful."

But the guide above says that this should only show up as an edit for the person that did the review, with no "reject" or "approve" action, which does not seem to be the case here. I'm not sure why that is.

If a reviewer is going to keep most or all of the original changes, they should really mark the edit as helpful. The "not helpful" implies that the reviewer is going to make significant changes to the intent of the edit.