First, you are trying to pick apart her reasoning for why she called you, making up a bunch of scenarios why she didn't call some other man......Does it even matter?
You say you do this because it's in your nature. fine, do it, but have no expectations attached whatsoever.
But I can give you the absolute simple answer to this. She called you because she knew you would do it. And you did. Like you said, it's your natural instinct. However, I doubt a little bit of the natural instinct because you wondered if you were help because you don't want her to be a jerk like she thinks you are.
Either you do these things or you don't. But don't attach scenarios and expections to it all.
