The argument that you just formulated is valid, and attacks the second premise of this argument. But again this point, you just raised is scientifically testable, since all is needed is to confirm whether from there is a genuine superposition from the perspective of observer 2(Wigner), at the exact moment in which observer 1 claims to know the outcome. This would undoubtedly demonstrate that there is a paradox. I believe that I raised such an objection in premise 3, and then mentioned this experiment in response.
I finally had time to look at Premise 3, and unfortunately for you, you’ve just happened to run into a solipsist. And not only that, but a solipsist that just loathes assumptions.
The first assumption that you’ve made is that the superposition actually exists as something more than just an abstract mathematical construct. But I don’t see how you can possibly address this, without running into the measurement problem. So you can’t prove that the superposition actually exists.
But should you choose to argue that even an abstract concept can’t contradict an observed reality, you still run into assumption number two.
The second assumption that you’ve made is that Wigner’s friend actually exists outside of Wigner’s own conscious awareness of them. From Wigner’s perspective there’s no contradiction between his friend knowing the state of the system, and Wigner not knowing the state of the system. The two things are completely compatible from Wigner’s perspective.
So you not only need to show that consciousness collapses the wave function, but you also need to show that there’s more than one consciousness at play here. Such that they can be in contradiction with each other. If there’s only one consciousness, and it’s Wigner’s, then there’s no contradiction. Wigner’s friend knows the state of the system and Wigner doesn’t. Perfectly reasonable.
Now if I’m not mistaken, proving the existence of two conscious observers is impossible, therefore you can’t use the Wigner’s Friend paradox to prove the existence of God.