This would probably be a very large factor in the score. I scored a 7 on a calibrated Dell UltraSharp (IPS) monitor at work. If I were to do this same test on my cheap uncalibrated Acer at home, I don't believe my score would be nearly as good. Even the difference between a calibrated and an uncalibrated cheaper LCD should be noticeable to most people.
Many people got very different results depending on the monitor they were using.