In answering this question, I am reminded of my experience with OC (pepper spray) when I went through LE training. The instructor asked if someone threatening to use OC spray warranted a deadly force response. Response from the students was mixed. Then he hit everyone with a shot of it, and re-asked the question. After seeing how the application of a non-lethal weapon was able to effectively disable everyone in the class, we pretty much agreed that a deadly force response would be acceptable. A hit from a stun gun or a shot of pepper spray could allow one to be disarmed with little effort. Once disabled, you can easily be disarmed, which means that your life is definitely in danger. My $0.02.