In every senario in that film, the guy who burst into the room knew which student had the gun, and went after that student.
How many times in a shooting situation like that does the shooter know which would be victom is carrying.
If you have 25 people in the room, what's the changes of the would be shooter targeting the one guy with the gun? What if there are more then one person carrying?
What if all the 25 were carrying.
Sorry, that video doesn't change any thing about my training or carrying.
Read this study, kind of blows holes in the video.