R.E.N. Spells Ren
Veteran
That seems like more reason to not allow cancellations mid-ride, as it could escalate the situation. A report would have to be made to Uber anyway, so best to just make the rider request the refund after they're safe.
Without canceling the ride, there's no way to determine when the meter should've stopped.
Protocol is simple: get out the car, cancel the trip. Uber should require you state why you're canceling tho.