You won't be able to if you look solely at the output. There are ways to check audit and verify the process by which said output was produced. They are also gamable but the cost of gaming them is not insignificant.
i think this is the scenario in question, if someone is lying about the source of an image
> There are ways to check audit and verify the process by which said output was produced. They are also gamable but the cost of gaming them is not insignificant.
this is interesting to know about. do you have some zero knowledge proof arrangement in mind here?