How could that be? It's because of the power of the fascist state. Joseph Ball was the 800 pound gorilla; the enforcer of the fascist state. And this was their photo. And, the people knew very well that the 800 pound gorilla did not want to hear any criticisms of the photo. You just answer his questions and try to get out of there as soon as you possibly can. You don't piss him off. You don't challenge the authenticity of the photo. It's the State's photo. They were vouching for it; so you don't challenge it.
And in case anyone doubts it, that headless guy in the Altgens photo is definitely fake. I proved it in Dealey Plaza.