Obviously it is really difficult to keep pushing with the same force when the car is moving but if the passenger was light enough and/our unconscious to the point of half falling out and the car was moving slowly enough it isn’t necessarily physically impossible. The woman in this case may also have thrown herself out in desperation after Elway made a gesture which she interpreted as threatening and trying to come after her. I doubt the story is credible without visible injuries but domestic violence charges are taken pretty seriously so we will have to wait and see...
In my car, I would have trouble pushing a 50 lb girl out of my car.
First, due to the center console, I would just barely reach the door opener with my right hand while keeping my left hand on the steering wheel. If and when I push the door open, I then have to release the door so I can push the girl out, but when I release the door, the girl can easily grab it and close it and if I am moving at any speed, the wind pressure will automatically close the door.
Basically, I must use 2 hands to push the girl out the door and then the vehicle is out of control.
Furthermore, to keep one foot on the gas pedal, I have to twist in a very uncomfortable position that robs me of use of legs or even the upper body to push the girl out the door.
All this assumes the girl is not wearing a seat belt which is another challenge.
I think the whole push the girl out the door while the vehicle is moving is BS.