I'd expect there to be evidence and precedent that directly contradicted her own word, as in all such cases.
I trust people to act in ways that further their own interests, consciously or subconsciously. They are actors, aka professional liars. They are pretending to be something they aren't. That's not a bad thing, they just are. They are better equipped to deceive you than anyone else in the industry, because they are already engaged in a consensual act of deception simply by being an actor. That's why it's called Willing Suspension of Disbelief, also known as Poetic Faith. It is sensible to want more than just their word, no matter how sincerely they speak it, and it is never wrong to consider additional details that add context and perspective to what they say.