Pedestrian claims

I saw a creative argument on a pedestrian claim a few days ago.  It appears that several insurance policies have been written to provide for medical payment coverage to people "upon" a vehicle which is how occupancy is defined in automobile policies.  As such, it appears that you can get medpay coverage from the at fault diver in addition to the regular coverage from an at fault driver since the pedestrian is upon them for being hit.  Sounds funny, but does appear to fly no pun intended.