I don't think there is anybody that would consider Floyd's behavior as being "high and obnoxious." He immediately asked officer Lane to please not shoot him, he thanked him when he was allowed to sit down, he asked him not to leave him alone, told him he was scared, asked him if he would talk to him, and not once appeared to be aggressive. He thanked them again when they pulled him out of the car and forced him into the prone position.
I don't think it really matters when they determined he "actually couldn't breathe." He had already said so 17 times before being restrained, and the bystanders alerted the officers over and over again, in addition to Floyd's cries for help, while Chauvin continued to kneel on his neck for more than nine minutes.