Chain forking does NOT change the # of shares. It only moves your valid to invalid shares. As I said, the total of valid+invalid was only half of what CGminer reported locally. I also configured CGminer to drop stale shares, with this option stale shares are not counted.
This is my true and personal experience. I have mined both RYC and WDC in his pool and the earning rate is definitely question.
There was talk of some chain forking going on earlier, maybe a chunk of the pools blocks got wiped out.