That's not what it looks like to me, but I will not argue this point - IIRC you have military training and probably know more about such things than I do.
Regardless, by the time of the tazing, he is already restrained. Do you agree with that?
Yes, I do. I said it a few posts earlier and in other places here, too.
Too many cops use the TASER as a first resort, and/or as punishment. It has its uses, but saving the cops from getting dirty or breaking a nail isn't on the list. Sometimes you have to throw down, and that'll get you dirty (usually) and hurt (sometimes), but that's just part of the job.
Yes, I was in the military, Army Infantry, but more importantly to a discussion like this I was a security officer for twenty years (and worked as a bouncer from time to time the while). I worked in some nice places, and I worked in places that could best be described as where God would do the insertion if He were going to give the planet an enema.
I fought with more than a few and subdued many more, and when I see something like that vid I think, "Those people aren't trained to be police officers (or security officers, as the case may be), they're trained to be courtesy officers." Watch how they act and react. Instead of getting control of him they're trying not to "escalate" the situation, the fact that he by his actions has already "escalated" it to the point where physical force must be used doesn't seem to have occurred to them. I've seen more than one with a badge have his ass handed to him in a fistfight, and heard of a few that were killed or permanently maimed in a gunfight, because of that attitude.