That said, it's her right to recline. It may be rude if the person behind you is unusually tall, but at the same time, the person in front may have a back issue that makes sitting upright more uncomfortable for them. And most seats don't move that far anyway.
I wonder how well she handled this to provoke that out of him. Maybe she said something foolish. Regardless, doesn't excuse his behaving like a child throwing a tantrum. What an embarrassing way to react.
People need to be mutually considerate.