I've seen at least three other cases of police refusing to offer help to a dying person and refusing to allow others to help. These are just off the top of my head.
OneTwo (What this doesn't show and which is hard to dig up now, but I clearly remember: The other veterans present tried to help Nick, but police forced them away and insisted that no one could touch him and that he would not be moved until he regained consciousness and asked for help himself. Of course, when he did, they responded by throwing him in a van for several hours. A horse had just stomped on his head. That could have easily been fatal and the severity of the wound needed to be check.)
And... I can't find the third one. I swear I posted the story on these boards 2-3 years ago, but I can't find it now. What I recall is a family called for help with their son, who was behaving angry and confused. I think he may have had a history of depression or other mental illness. An officer showed up and ordered to kid to surrender to arrest. He didn't comply, so he shot the kid with a taser. He still didn't comply (the police story was that he then attacked the officer, but the family witnesses claim he only stood there and balled his fists), so he then shot the kid with his gun. He then refused to allow the family near their son and refused to call for medical help for hours afterwards, essentially forcing the family to helplessly watch him die in front of them. The father then claims to have discovered later via FOIA request that it's department policy to refuse medical aid to someone that has been fatally wounded by an officer, basically because it causes less trouble for them that way. I can't easily find this one on google either,
because searching for similar cases where parents calling for help with a mentally ill child resulted in killing of that child brings up dozens of cases in 2014 alone.