Those who scored significantly lower than expected, do you suspect error in the marking?

I haven't experienced this personally, but I have seen many people saying that they scored much lower that expected. And I saw lot of Us in people's results here.

One would assume that Cambridge's grading is top notch, but many people are saying that there is something amiss.

What do you guys think? If you want to share a personal example, please include your predicted grades (Specify if it's official from your school or just DIY), actual grades, how confident you were, and what you think was your raw mark.

This is justout of curiosity. I cannot offer my personal opinion on this matter at the time.