The live fire at targets and the flickering of the helmet mounted strobes would have looked like a firefight with some fire directed at the aircraft. Not a situation where a pilot would have been very hesitant in returning fire. I would'nt have wasted any time. I feel sorry for the pilot, he/she should not be punished anymore than the knowledge of the error will bring by guilt.
It's similar to that sub captain who sufaced under that Japanese fishing boat. A one in ten million chance. Or maybe 50 million.