I don't know much about police technology, but, I would think, since they were handling the situation for a while (as stated by the news clip) and the fact that they knew they were being filmed, why would they throw out the rule book?
15' isn't far, and not all police officers have them/are trained (as per interview during news clip).
Frankly if you do that, you get what you deserve.
Buddy of mine a few years back saw a guy arguing with a cop in downtown Halifax. To this day he regrets not standing close enough to hear exactly what the drunk was saying, so he'd know NEVER to say that. Cop took his billy club and beat the shinguard out of the drunk.
Use your head, if the cop says "put the knife down" put it down, if the cop says "get in a cab and go home you drunk" get in the cab and go home (or to another bar
)