If there are charges pending and the investigation is ongoing ... not too weird. Also, the driver might not have seen a lawyer .... and the police might not want to set that up until the prosecutor decides if further charges are warranted.
This one will be interesting because the driver admits to putting the car in reverse and backing into the cyclists. Possibly the DA is weighing whether the guy was Mirandized and whether the people who might have witnessed that statement can stand up in court. DAs like to win cases ... the bigger the better, but they won't go big and risk losing.