I think it's just the wrong implied use of calm. There's no way her body was in a calm state. It's just that adrenaline adjusts the bodies resources, which could create a feeling of mental calm. But describing this as a sense of calm is a world away from the calm some Buddhist up on a mountain experiences and other such uses of calm.

I guess my issue is just describing this as if it was just another day commuting to the office. The stakes were very high and her description and this article almost imply otherwise.

I'll keep my functioning spine and legs thank you ; )