The good Lord was looking over you when that happened. I am relieved that you were not injured. This was a wake up call of sorts. Just because a power tool is small does not mean that it can not hurt you. The average speed of one of those is about 10,000 rpm or greater so if it flings something, be it the tip in the chuck or something that the tip gets a grip on that object is going to be flying with considerable force. There is a very definite reason why safety glasses / goggles should be worn as well as a respirator / dust mask. I am glad you were not hurt but this just underscores the need for shop safety equipment. It's not doing you any good if it's on the wall or in the drawer. < steps off soap box >
DW