And if you had done the same thing: flippin the bird while driving your employers vehicle, while being on the clock, and in front of your bus riders, you too should be fired.
I still don't think it's a fireable offense. It was a stupid thing to do. Maybe her so-called "pattern of behavior" put her in the should-be-fired category. Free speech may not be exactly what you want it to be, but we are free to flip someone off should we so choose.