... which is actually a completely reasonable assumption from her perspective.
People at her level of power being held accountable is the one-in-a-thousand exception. It almost never happens. In a very real sense, she was just extremely unlucky, and had undoubtedly witnessed countless others commit worse crimes without any negative consequences for them.
This is also the answer to questions like "How did those cops think they could get away with murdering a man in cold blood while being filmed by half a dozen cameras?" It's easy: Because they had seen others get away with it, time and time again. Statistically speaking, a cop murdering an innocent citizen has about as much to fear as a regular guy parking in the wrong spot. Indictments are not the rule, never mind convictions.