This type of thing is exactly why I have my rule in place: If a book is reviewed on RAR, I will not edit the book. If such an author were to contact me, I would send them my list of "recommended editors" built from recommendations from authors right here on KB.

Although, I have no qualms about offering to do their
next book.
However, in the person's defense, it could just be that they are scanning Amazon in search of books who have received reviews stating that the book needs an editor. There are certainly plenty of them out there without anyone ever needing to write the review themselves.
I freely admit to wanting to offer my services when I see reviews that say things like, "Wow! This was a great story. I would have given it five stars if it wasn't so filled with typos and grammar problems."
That's not greediness on my part, but an ache to help an obviously talented author. Heck, there are even times I want to offer my services here when I see threads about authors getting "editing" reviews. I sit on my hands to keep from offering because it feels like "ambulance chasing."
I don't actually do that, though, simply because I don't want my intentions to be misconstrued, nor do I want to be accused of writing the reviews myself.
Of course, I can afford my lofty moral code because I stay busy. Perhaps that person is just starting out and needs the business.