The footprint looks like a canid to me. Why do they need to estimate its size from the footprint/video footage, why not put a rule in the spot where the cat/dog/whatever walked past? looks like a fox with a blunt nose to me.
its hard to say as there is nothing for a ref. it could just be a norm cat with out a marker for how high it is its no good. and the cam seems to me that it is close to the ground as the blades of grass are coming up in front of the cam. witch looking up would make anything seem bigger. and for the tree in the back for all i know that could be a rose bush in a garden some were.
if i had to call it i would need to say this is a fake.