You are allowed to resist an unlawful arrest at any time, so I don't know what you're talking about. You can only use the force part if met with force.
So 400 lb. man resists arrest, because there is no legal, suspicious or probable reason for him to be arrested. Legal.
The cops then use excessive force because he is too big for them to subdue otherwise. Illegal.
The man is then within his rights to match that force. Legal.
So we have large black man 2 - cops 0 on our legal scoreboard.
Problem is we live in a police state where it's generally accepted to just bow down and take it for fear of being shot or beaten. It shouldn't be this way and change NEEDS to happen.
Once again, you are a cop. You are here to protect me, and serve me. Not murder (which is what this was) with impunity.
I usually agree with your posts man, as I lurk here often but your backwards on this one. The USSC and the trial courts specifically made mention in this oft quoted case that you can only resist if its effected with excessive force. Internet heros have twisted the ruling to fit their argument. Your sentence " because he is too big for them to subdue otherwise" basically nullifies your "excessive" argument because your basically saying the force leading up to that was insufficient to achieve their goal, therefore an escalation in force was necessary and not excessive.