The mistakes I have found on PA cue sheets (that I remember) happened when they reversed a course. They used to always get Bill O. to pre-ride, and he famously never used a GPS. The problem with that is when he had the course memorized and for whatever reason they changed the cue sheet. Like reversing the course, for example. In Pennsylvania particularly, I think a good cue sheet requires that a second person review it. I made a mistake on my fleche cue sheet (right instead of left) and none of the other team members had looked at the cue sheet at all before the ride, so I have to admit I was somewhat unapologetic.
PA uses a system where you mark up the rwgps cue sheet and feed it through a program. It automagically generates a really nice cue sheet for you. There are other versions of that, but this is really nice. Of course, for me as a perm creator, I don't have to do cue sheets any more, which is a big relief.