Well, you leave a loophole when you qualify the prediction as almost perfectly accurate. With this loophole in place, there is always a possibility that any prediction is wrong, and thus the rest of the reasoning doesn't go through.

I didn't think about it but you're completly right, because if his predictions would be perfectly accurate this would also mean that they are in fact inevitable and the whole argument would become nonsense in the first place.

If by spontaneous decisions you mean those decisions that the fortune teller did not foresee, then there may still be room for those. But they will not change whatever he correctly predicted.

And that is what i meant by saying that for him the future becomes inevitable, because at the exact same instance he foresees his own decision to act it becomes the reason for the future event, as i said above. And your assumption would lead to the same, as even though he did not foresee his spontaneous action, the future remained the same, so that his decision to act and the act in itself still did not change anything.

There isn't a right or wrong answer to the question, so I wouldn't worry about it too much.

My goal with this assumption was mainly to clarify if i maybe had made a logical error in one of the steps to this dilemma. As i acknowledged above the solution to this thought lies in the degree of accuracy that the fortune teller has. If he has perfect accuracy then the argument becomes nonsense as it is obviously perfect and there is no room for mistakes. And what i have now come to realize is, that in the instance his skill becomes non-perfect, you could argue that he simply did not foresee the consequence of his decision to act, which would fall in the 0.01%(for example) margin of mistakes he ever makes.