My guess, the moving animation is now triggered the whole time you press a moving key (left,right). So the the animation for firing will never be played completely and the the end of animation event will never be triggered.
It also looks like the running animation is only the first frame, because it starts over and over again.
You could differentiate between only running and running and fire together.
It's hard to say what is the best without seeing the wohle game code.