First, you see how ridiculous is the claim that a perfect vee neck shadow was cast by Doorman. Look how irregular mine is. It is meandering. The perfect arms of the vee on Doorman are the shape of his t-shirt. We are seeing the junction of his shirt and his skin. The white that you see is the shape of his t-shirt. The claim that he was wearing a high, round t-shirt which got obscured by shadow is ridiculous. It's just his t-shirt; Oswald's t-shirt.
It sank down like that, and that is what we are seeing on Doorman.
The Doorman is wearing Oswald's t-shirt. Now, unless you think Lovelady attacked Oswald and stole his t-shirt only to return it to him afterwards, then you are chit-out-of-luck. The only one who could be wearing Oswald's t-shirt was Oswald.