How to get yourself kill't 101:
1. Escalate situation by taunting potential attacker
2. Draw blank-firing gun and point at potential attacker who is now an attacker due to #1
3. In case attacker thinks the gun is real, fire a burst directly at him to demonstrate that the gun is, in fact, firing blanks
4. Look bewildered when attacker is suddenly emboldened by your foolish actions. Assume the fetal position.
That other vid where the office worker pulls out pepper spray, then a stun gun, then the blank guns reminds me of the looney tunes cartoons where two characters keep pulling out bigger weapons. Although the acting isn't quite up to looney tunes standards.