Isn't that somewhere in the Bill of Rights?
In the first scenario, if someone chooses to randomly shoot a police officer then nothing can be done. This is generally true throughout society. If people choose to randomly shoot others they can mostly succeed. This is not an argument for an officer having a gun, but for less guns to be involved in society in general. Even if the activist or newscaster had a gun drawn from the beginning the outcome easily could/would have been the same.
In the second scenario, there's no reason for a gun to be involved over something less lethal like a taser or a baton. This is essentially a misdirect after people are freaked out from the first scenario.
In the third scenario, again why is a gun involved? Similarly a taser or baton would get the job done. Or actually using other tools like handcuffs rather than shakily pointing a gun at someones back, which is begging for an accident.
All of this to me ironically paints a picture of guns unnecessarily escalating situations, rather than the point they were trying to make.