When police "don't do everything right", people die. They are given extraordinary leverage to use deadly force, and are assumed to be telling the truth in a court of law. And we have seen that almost universally, police will protect other police who abuse their power.

These are not equivalent. Police who do bad things not only cause extreme harm, but terrorize people whose protection is the whole reason we gave police the monopoly on violence in the first place. This is not a "two sides to a story" situation. This is a situation where one side has all of the power and far, far too much documented abuse of it.