Floyd had a history of swallowing his drug stash when confronted by police. The time works pretty well. He also had methamphetamine in his system and a 90% blocked coronary artery to his heart. He was a ticking time bomb. You can't possibly hold a cop responsible for that even if the restraint is what put him over the edge, there is no way a cop could be reasonably assumed to treat every person as if they could die of a heart attack or overdose at any moment.