Example: I'm at a wedding and the photographer takes an awesome photo of my grandmother. If I don't want to communicate with grandma, who commissioned the photographer, I have the option of going directly to that photographer for a print.
I would say that since this was (likely) a private event on (likely) private property and that the photographer was given permission to shoot from the person hiring him (and the person that paid them) that the photographer does not have cart blanche to run around selling prints. Different from "street photography" art prints.
For example, a boudoir session. Would you imagine the photographer can go sell prints of that to your neighbor?