if a provider has 1 bad review out of 5 then what does that say about the bad one? is it fake or what?

...he had hygiene issues. Maybe she was having a bad day.  A common acronym on TER is 'YMMV'.

Check all the reviewers other reviews to see if there is a pattern in the reviews.

If you're a newbie, you shouldn't see a provider with only five reviews. Go with someone more experienced, a sure thing.

...And there are those people who will not be satisfied with the service received.   As mentioned, it could be a myriad of reasons why the single review is bad.   Perhaps the woman was having a bad day.  Perhaps the guy was having a bad day.   Who knows the specifics unless one reads the reviews of the woman?

Reviews are always subjective & depends a lot on what the reviewer was looking for.  That said, you need to look at the number or reviews by each reviewer & even how they scored the other ladies.  That should give you a good sense of the reviewers.
You could PM the reviewers & see what they say.

I don't hold a single low review against a lady but I do look closely.  2 low reviews (in a single page of reviews) I'm suspicious that the lady might be "moody" & with my luck would catch the poor mood.  I'm not inclinded to risk my hobby donations, opportunities very much.

5 reviews is not a lot.  I might call this one either way...  depending on what I'd found out.  
I might just hold on this one pending more reviews.
skb