Please understand the overall score is not the average of the other scores, it is the overall impression of the shoe. Each tester provides their overall score (which can take into account fit, feel, cosmetics and other intangibles not scored in the other sections) and the average of those scores is posted as the overall.
In regards to scores, they are as much opinion as the comments. The testers are not always the same from review to review, people's opinions change over time and I have seen testers go from scoring tough to being much more generous as the years go by. I think that when a number is assigned to something, people tend to take that in a more factual way, but in the end it simply is a reflection of the findings of a group of testers at the time.
We do our best to be fair and accurate. When our reviews are glowing, we get accused of being positive just to boost sales. When we ding something that others like, we get accused of being biased, clueless or what have you. That being said, the scoring is as accurate as possible and the overall score stands alone as the average of the scores for the overall impression of the shoe.
Hope that helps.