Heh, I actually said it was my interpretation. And just like The Prestige, my interpretation is that the ending is clear cut, and not ambiguous at all.|
I guess I should also reiterate that it's not necessarily empirical evidence that creates the argument. Of course there are plenty of references, hints, metaphors which you can use as material to support an argument, although these themselves can only be interpretations.
What clinches it for me is that Cobb does not check to see if the top stops spinning. Why not?