Certainly we expect humans to have more intelligence than animals and to know better. Sure, it is due to your expectations. It is easier sometimes to feel compassion for a dog or a cat than a human being. And it is easier to have equanimity towards animals because we simply expect them to show their animal nature. But when we are dealing with humans, we see that humans are capable of many different things, they are capable of great goodness, they are capable of great evil and they have the capacity for abstract thinking, rather than just dealing with their instincts. So it is much easier to forgive animals because we realize that they go a lot on instincts.
We expect more from human beings because they have the capacity for rational thinking, they have morality teachings, they have this higher capacity, so of course we expect more from humans. When humans do not manifest their higher capacity, when we know they are capable of it, then it is much more difficult to have equanimity. So yes, we have to realize that we do have more expectations towards humans than we do for animals because humans are capable of rational thinking and understanding moral teachings.