Has anyone here ever handled a grenade, much less actually thrown a live one?
I have, and it ain't like TV where there's a boom and everyone gets blown over, stands up and brushes themselves off. If someone has such a weapon and they can not be safely contained and isolated, then they need stopping before they can deploy that weapon. The exception would be if they were already amidst a target rich environment, then in that case you have to weigh the risk to the innocents of taking no action against the Tango, against the risk of him letting the cocking handle fly. In that situation there isn't a right answer.
The scenario shown in the video would be unlikely to play out here. However, the guy is on a small, fast, agile vehicle with the ability o go where cars can not, and the officer was able to take decisive action and stop the Tango with no collateral harm. In the tactical sense he was 100% successful.
It's a military level problem, and it's not realistic to always expect a civilian level solution.