I don't think the pilot handled it very well. He should have simply said "we have a medical emergency" rather than "someone has decided they don't want to fly with us tonight".
I can sympathize with her, but unless this was the woman's first panic attack, she may have been able to have some medication on hand. Then again, she may not.
If I were the airline, I would ban her until she produces a doctor's note stating that her condition has been addressed and she can fly safely.