For a while (for a much too long period of time & around the time that they hired many new graders), there was a common theme among the graders notes. That theme was what I & others referred to as 'phantom flaws'. There was a plethora of defects being noted by the graders that were not there. I'm not sure what the reason for this was, but many, many people experienced it. It was almost like the graders had to do it (or thought they had to do it). It hasn't been reported in a while ... that I'm aware of.