By putting a stopwatch on the footage, it looks like the whole event took about :18 seconds from start to finish.

From just kicking back on a regular day at work to fighting for their lives in a matter of seconds. It that short a time period, people don't think, they react. I am not going to judge that security guard for what he did, because for minimum wage, or something close to it, he put himself directly in the line of fire to protect others.