Matt, I am so sorry and feel for your friend losing her kitty Kat in such a horrible fashion. JT is on the money and in my opinion neither of those animals should have been on CP unless on a leash or carried. If they were….well.. Bylaws people!!!! But… that does not forgive the fact that this animal/dog is most probably a dangerous animal and should be reported to your local council.
Best of luck to your friend in finding some resolution.
Cheers CBF