I have to disagree with that blonde zoologist who looked at a video of one alleged Beast sighting, and pronounced it a domestic cat. I have never seen a housecat that slender! Let alone, one with a tail that long.
It looked more like all the pictures I've ever seen of the African cheetah. Although, I'm unable to explain the grayish-black coloration of the fur. I know that the so-called "king" cheetah is actually a partially striped color mutation of the common cheetah. But, I've never heard of melanistic specimens.
Could one of those released exotic felines have included a few cheetahs? And, could one of them have mated with a released black leopard? Obviously, only time and further research will tell.