This article says that he wasn’t continuously running his siren. One of the other articles posting about this story said that witnesses in the area said they could hear sirens and that the victim was running.
Not claiming any truth or anything else. That info could all be false and I’d still make the same claim. Going for vehicular homicide against an on duty cop responding to a call, even when he was being a dumbass, just isn’t going to get a guilty verdict for homicide.