To be honest, CMC has been accused of manipulating prices and display fake volume several times so i wouldn't be surprised if they messed with something yesterday.
I had read about it, was it true at the end? I don't really see the kind of manipulation that can be done by changing prices on CMC,
Yes, there were reports before on how they manipulated the price few times and how buggy they were. CMC isn't really a viable source of price but if you have been used to it, don't rely on their stats and always check other sources for volumes too.