HARLEY!!! My Hero
You are so lucky! Do you think your cat would've killed the ferret? My ferrets live outside in a screened cage and they get loose occasionally and we have a ton of cats outside and the cats don't seem to want to mess with them. I think it's the smell...or maybe cuz the cats can see them all the time and they just aren't interested. My cats are hunters too, they eat anything that moves generally.
I'm glad Harley didn't give you a chance to find out.