My department calls the paramedics anytime someone asks for them even if the injury appears made up. Most of the time it is because they would rather spend time in a hospital than a cell for the night.
Likely because this is a prison with professional medical staff including doctors, psychiatrists, nurses. All who would have made the ultimate decision to not seek more medical help. The officers would have only been able to refer him to the on site medical staff who rejected any treatment. But the OP and many posts are fuck the police" regardless of this. Not surprising.
Please explain further how the cops involved have no cuplability. I don't quite get your logic.