Man Accidentally Killed by Police Choke Hold in Staten Island

[I spent the winter writing songs about getting better]

a) Did the police's use of force violate protocol, and if so to what degree? Again, the fact the police used physical force on a huge guy who was resisting arrest, and the obese guy died of a resulting heart attack is by NO means dispositive of the issue.

b) If yes, what impact, if any, did the deviation from procedure impact/cause the man's demise?

Uh as the OP states using chokeholds is a violation of NYPD policy.

[I spent the winter writing songs about getting better]

Something has to be done about cops from the federal level.  Police brutality is rampant and within the structure of an individual station, no doubt this behavior is provoked and promoted.  Let's start with higher standards and pay for those who are tasked with law enforcement and go from there.  As it is, too many cops out there (hell, more than a few slipping through the system would be unacceptable) are insecure high school losers who beat and prey on the helpless for their own sick amusement.  These are the exact types that should not be given corrupting power. 

For things like this the feds often do handle it pretty well when the local authorities don't. For example see the Rodney King beating.