First, I expect that the victim’s family will be suing for negligence (https://www.forbes.com/advisor/legal/personal-injury/reasonable-person-standard/).Unless prosecutors can dig up an actual answer to that question beyond conjecture, there's no case.
Second, I think that if Miller wasn’t a probable lottery pick and the star of the most popular team in the state, the police and prosecution would have already been putting together a case. If someone has a shaky explanation, you poke at it. This is at the least laziness on the part of the police and prosecutors.
Miller would have a much better defense lawyer than his buddies, though. It’s easier to convict the people who have no resources.