Very cool headed cop but I'm not sure he did the "right thing".
There is a risk that using less than lethal force may not be fully effective.
What if the taser had missed or malfunctioned? The outcome could have been very different.
And they do miss and malfunction or become prematurely detached .
The way I see it, the guy was going for his gun... That means "all bets are off".
He could see the cop had a gun in his right hand and he still went for it.
It may be hard to deal with it after but the cop would be fully justified in using lethal force in this situation.