So the 16 month old was pulled out of a FF seat? I understand now that she was just moving the car and kiddo was probably sitting in older siblings seat.
I guess I'm just wondering why you would think to call 911 for a FF child that age? While it's certainly far from ideal, assuming the child meets the car seat manufacturers minimums, it is well within a parents right to make that choice for their child.
In that circumstance I would probably take the opportunity to discuss RF, especially given the recent release from the AAP, but I definitely wouldn't call the police over it.