It depends on whether the author has established credibility on this board in some other way, with each of us being the arbiter of whether that credibility has been established for ourselves.
Before the crash, I noticed a couple of guys whose reviews and comments were exclusively about a couple of ladies. That screamed "mandle" to me. One "guy" was making comments on behalf of a lady who left the hobby for a couple of months two years ago and reestablished herself in another city under a new name. I'm pretty sure his reviews and comments were made by her as she sought to get reestablished.
The beneficiary of the other "guy's" comments was given a vacation by the mods a little while after I noticed his pattern. (I did not RTM either, BTW.) He hasn't shown up since, and she's no longer active here.
But a guy who has cred around here reviewing the same girl several times? I have no problem with that. I wish mtabsw, Silver Bullet, and White Tiger would review more.