If Lovelady flannel shirt hanging loosely , then possibly the wind gusts of 15mph at the time could have moved the loose shirt hanging on his right side outward in a way to create an shadow from the shirt.
Also, if his right arm is moved outward with elbow bent, it might cause additional shadow on his right.side.
I don’t a have a computer shadow program Nor have I have made a scale model of the front entrance and placed some adjustable figurines , so it’s only a reasoned speculation I’m
Offering here.
If someone has the shadow analysis graphics program, please feel free to test the bent arm/elbow possible positions and the shirt side moved outward farther from the right side of the body.
I’ve seen some previous computer shadow analysis in another thread that may be still here, however it was positioning a body with right arm hanging straight down near to the body and shirt as tucked.