It IS possible:
Based on the mountains being visible in Gannon's sunglasses, his face--ie the front of the truck when backed in-- faced west and slightly north.
In this area, and that time of year, the sun is very low in the sky and sets on the left side of Pikes peak at around 5pm. The sun would appear West by Southwest at around 2p and complete its arc at approximately west by west by Southwest (a little south of due west.)
Therefore; at around 2pm, stationary objects, like a telephone pole, the vehicle to the north of the truck, etc., would have been casting shadows in an approximately East by Northeast direction, relative to the sun.
The driver's door sweeps an arc from slightly south of East to approximately west of south by Southwest (possibly more westward motion), and the rear passenger's *would* sweep an arc from slightly north of East to approximately west of North.
The punchline?
Yes, along it's arc the driver's door casts a shadow under the truck and in the precise location as the rear passenger's door is alleged to be opening.
Don't even get me started on proving the date and time of each RD vid, without a date or time stamp. I mean, what's next? The sun is a liar out to get her too?