If you take a look at virtually any Google Local listing with reviews, you might notice that Google is showing twice as many reviews, as the company really has. For example, my company listing shows a review count of 4, but in reality, I only have two reviews.
Here is a picture:
Yes, Google shows the number 4 but only really has two reviews listed.
A Google Groups thread has confirmation from Google that this is an issue that they are looking to address:
It's a known issue that we're working to resolve. Sorry about that. For now, it's best to just assume that you only have 4 reviews.
Forum discussion at Google Groups.