a FA who go against the authority of a captain has no place in this industry.
the captain has his crew, his plane ,his license and his power.he has final authority. It 's printed black on white.Even the OFAC can not do anything against the captain' decision.He can even break air laws if he wants.
Easy was right to kick this lady out, she can find another job.
what is the job of a FA ?answer: take care of the cabin. do you have any authority in the cockpit? which one?
if you want take decisons on board of an airplane , become a pilot first, then you can play with rules as much you want.