His death was a purely random event.
He was taken into custody on 31 prior occasions and survived all of them.
Hundreds of thousands of arrests will be made this year: in one case the arrestee happened to have a heart attack during the process - when is the last time that happened?
That's neither "legitimate" or "illegitimate" - it's just statistical randomness.
Why do you jump to the belief this was a heart attack? What part of a chokehold for an unarmed man selling untaxed cigarettes is jusified?
I agree with your points some of the time, but on this, your head is firmly up where the sun doesn’t shine.