People, let's try to be much more polite in this little corner of the Internet. Save the barbs for some other site.
Back on topic, I must have seen a different movie than everyone else. The movie I saw was an indictment of a company that keeps dangerous animals without telling its employees just how dangerous these animals are. It's a movie about a cover-up, not about animal treatment.
When a lion attacks a zoo or circus employee we all know that this is a natural behavior of the lion despite years of effort to suppress it. Why would anyone not expect the same from any apex predator? Or from certain breeds of dog, for that matter? Check out the TV show about the people who tried to raise a wolf as a dog. They start cute but nature wins out.