The narrator definitely has some confirmation bias believe me. That said it was more his central point that I agree with. If you are going to carry a weapon don't assume that the weapon alone is a "magic wand."
As for people having their guns taken from them, while there is no statistic for officers who are "simply" disarmed, a number of studies have been performed that show of Officers who died from gunshot wounds, ~10% were shot with their own gun.
It's one of the basics of being a police officer; every call is a gun call, because you carry one into it.
It's also one of the reasons we can't afford to lose a fight. It hasn't happened often, but I have had idiots go for my gun. And I practice protecting it.