I can’t think of an explanation that I’d consider reasonable. I’ve been through two police academies and was taught in both of them not to kneel directly on a subject’s neck or spine. I ESPECIALLY can’t think of a reasonable explanation for why the officer continued to kneel on the subject’s neck for several minutes after the subject appeared to lose consciousness and become unresponsive. Even if this turns out to be an excited delirium death that couldn’t have been avoided had the officers done everything right, the guy who kneeled on the subject’s neck sealed all their fates.