Once in a lifetime situation

[SF]

In a game tonight I had a situation that I doubt I will ever seen again, no matter how many years I umpire, but I thought some of you might enjoy this story - also a good rules knowledge test.

I'm behind the plate, no outs, bases empty. Count is 1-2 on the batter. A pitch comes in, the batter takes a mighty swing and misses. The ball hits the catcher's glove, but she fails to catch it cleanly, and it pops up into the air. In the meantime, the momentum from the batter's swing has twisted her around, and the bat, held in her left hand (right handed batter) swings around and contacts the ball (the batter's back is to the plate, momentum has completely turned her around.) The ball then goes into fair territory.

So, for all you rules gurus, what do you call? And has anyone else ever seen anything like this?