My scooter releases the engine below 15 MPH so I slow to 15 MPH, cut engine, ensure engine shuts off, turn engine run switch back to run position so the scoot registers the miles coasted, prepare to re-start the scoot when balance becomes difficult. Go here https://auto.howstuffworks.com/cvt2.htmto learn how CVT's work. I can explain it but this link is pretty good. The belt disengaging the engine happens below 15 MPH due to the centrifugal clutch slowing down and the clutch shoes releasing the drum.

You also need to GPS your speed and mileage to get a true reading of both...Scooters are notorious for errors of 10-15%

Unfortunately, the scooter is now totalled (catastrophic frame damage). On the bright side, nobody got seriuosly injured :-)