Suicidesoldier#1
As sad as it is, the guy died of heart failure. The action ordinarily would not result in someone dying, so using a grappling maneuver as he did to arrest a man in as peaceful a manner possible more or less followed protocol.
The sad reality is, even protocol is not perfect. Occasionally, people will die even when you do everything perfect, or by the book. You do the best you can in the situation you're given, and that's all you can do.
Whether or not the chokehold that the officer used was protocol is debatable, and that is a valid point. The question of the chokehold's justification or the specific hold used should be part of the discussion.
However, that still leaves the question of whether or not he should have continued the hold while Eric Garner was on the ground saying "I can't breathe", while four other cops jumped into the struggle.
Still, if the hold used was, in fact, protocol, then perhaps we, as a society, should have a larger discussion on what the protocol should be, or if it should be changed.
To be clear... I'm not refuting your argument, merely offering my perspective on it.