My guess is those reviews are lost to the ether, as the database is in read-only mode.
IF my suggestion’s easy/fast to implement, it’s to put a spanner into the works, so to speak, do basically disable the review.php script so the user gets a 403/404 error instead of being led into thinking their hard crafted review actually made it to the author. (Of course, that’ll change this tech support topic to “why is reviewing busted”?)
If it helps, @GeorgeGlass I’ll lie and claim that it was a beautiful and glorious review…. or that it was a flame and this empty review is better