Iâ€™m not worrying about the mathematics. If thereâ€™s a problem there, it is with the physics (including the mathematical modeling) rather than with the mathematics. But physicists are well aware that quantum particles donâ€™t fit our classical mathematical models.

I expect this doesnâ€™t actually show that something really strange is *necessarily* going on here, in that I have a rough idea of how Bohmian mechanics could explain the result of a similar non-relativistic experiment without any weird contradictions.

It comes down to the fact that â€śmeasuring whether two particles are in the same boxâ€ť is not the same thing as measuring the position of both particles and comparing them; it may in fact correspond to an experimental intervention that doesnâ€™t (from a Bohmian perspective) accurately reveal the pre-measurement particle positions, because the experiment itself influences what those positions are.