If the poster with the review has reviewed other providers, you can search them and see if his ratings compare well with others. If his only review is for that one provider, and it is a very high rating, some red flags will go off for me. If he has rated many girls (especially if it is one one that I have seen) and his ratings are similar to other reviewers, I'd put more weight for that one review.

If he reviews exactly two girls a month, he is probably doing it for free VIP and that, in my opinion, is far less reliable.

However, follow the previous posters' suggestions.  Be extra thorough in your research.  Does she have reviews somewhere else, there are other review sites, I just can't name them due to TER rules.  Does she have a website?   Where does she advertise?  Did you check her pictures?

It is not poor taste to ask a reviewer for additional information, but look at his track record on reviews first.  Personally, I would be hesitant to see someone with only one review without checking her out completely.

Swim

You could also try and set up a meet and greet at your local coffee shop, food court, library or other public place.  If she ain't the girl you thought she was you are not out much.