“This should indicate to the officer to grab his Taser, not his gun.” (From the video.)
I disagree. The guy with the knife (which I never saw) was inside the Tueller distance as far as I could tell. If the Taser had missed, quite possible in a mobile situation, the cop would not have had time to draw his gun or maybe even fire a second shot from the Taser.
That’s not to say the cop could not have backed off and waited for backup, just that if he was going in the Taser was not the appropriate option for the situation.
And of course, I offer my opinion as one of the chairbourne, not someone on the front line.