My guess is that he was already high, still had more drugs on him, and when the cops got called and went up to him, he swallowed the rest of the drugs to hide the evidence. The optics still remain terrible for Chauvin. If he wasn't ego tripping so hard, he would have gotten off him as soon as he went limp. That's a sure sign that something went wrong, especially after the guy went from being extremely resistant to completely still.