I have seen these pics on internet and i don't think that it was a rat. KFC people take raw chicken parts, place them in a tub full of seasoning and flour, they powder it nice and even then fry it... if it was a rat, then at the time of frying he can easily recognize it. I think this man done this for gaining some free publicity and to get famous.
It's easy to tell if he was served fried rat, just sit him down and serve him a mix of fried rat and fried chicken.
See if he can tell them apart.