Notice how, by being front and center, they insured that his blue Glock made absolutely no difference. Watch again. Before he's even gone for his gun, he's been shot, It wouldn't have mattered whatsoever whether he had a gun and was killed or was unarmed and was killed.
Ditto on the Diane Sawyer police sim.
What does this teach us? To the anti-gun Liberal, it teaches that guns are bad, Mmmkay? You shouldn't have a gun, Mmmkay?
To the thinking human being it teaches that no amount of training can give you superhuman reaction times, or make the bad guy give you sufficient warning that he's about to do something bad when they barge into a closed, essentially windowless room and almost immediately begin shooting.
To the trained personal protection sidearm carrier, it simply reinforces the need to stay out of condition white. Someone in condition yellow could more easily recognize that the man who just burst into the room is holding a gun even before he's opened his mouth, and then entered condition red and begun liberating his own sidearm for defense sooner. But these 20/20 scenarioes gave zero opportunity for condition orange, which seldom, if ever, happens.
Even in the VT massacre, most of the victims knew that it was SHTF time because Cho was shooting up an adjacent classroom, and they had time to prepare to barricade the classroom door.

Originally Posted by
WikiPedia Before Cho began shooting, several student eyewitnesses said he poked his head into a few classrooms. Erin Sheehan, an eyewitness and survivor who had been in room 207, told reporters that the shooter "peeked in twice" earlier in the lesson and that "it was strange that someone at this point in the semester would be lost, looking for a class".
-- Virginia Tech massacre - Wikipedia, the free encyclopedia
When they "Nudge. Shove. Shoot.",
Don't retreat. Just reload.