When seeing video footage of real life events or reading accounts where folks note that something could "happen quick," what you realized is that the perception of things happening so fast are often events that happen fairly slowly, at normal speed, or have considerable foreshadowing leading up to the event. The reason the events happen so fast is because the person was unprepared for what they encountered and by the time they grasp the situation, they were already behind the curve on reacting.
Chris was surprised by a stranger peering in through a less than substantial barrier, a screen door. It is a great example of a non-event that could have been very bad had the stranger had ill intent.
"If you look through your scope and see your shoe, aim higher."
-- said to me by my 11 year old daughter before going out for hogs 8/13/2011