Reading the whole report it sounds like there was a bit more going on here. Normally, you don’t break 15 ribs falling to the ground and being restrained. That is more than half his ribs, unless he stole a rack of ribs, in which case there were 15. Even knocking someone to the ground should not result in 15 broken ribs. Maybe he has osteoporosis? I wish they had been clearer on the mechanical asphyxia. They probably sat on him after they broke his ribs.
Another article says one of the employees performed CPR. That can break ribs.
I like the way you think.