[Jach]

Um, the original formulation needed no magic box. The original formulation is also equivalent to setting up a gun that fires at a cat you're watching the whole time iff the next photon you send at a beam splitter is detected by one detector over the other.

[jerf]

In thought-experiment-land, it may be, with the right thought experiment.

In the real world it most emphatically is not equivalent. And also in the real world, a lot of people get very confused about this.