Overlooking important points
I've just finished watching this for the first time. I knew from the boards that there was some skepticism about Ron's involvement in the deaths, so I was interested in watching it first hand.
I believe the only thing Ron is guilty of (besides dubious taste in wigs...) is the poor decision of allowing his vulnerable wife around a cat that had only recently killed its trainer. However I think based on the fact that he is trying to stimulate and engage her, and the fact that she is an experienced cat trainer, makes his poor decision more understandable.
I think its ridiculous that anyone would blame him for Chuck's untimely death. Ron did not create an elaborate scheme to trip Chuck and hope that scares the cat enough to attack Chuck...the cat's role is to unpredictable, and I believe Ron loved Chuck, even though the relationship is unusual and uncomfortable for most people to accept...I can't understand it.
I think this is a tragedy, and it deepens with the suspicion that is thrown at Ron. Poor, strange man.