Very few comments on this one, but my confusion hasn't been extinguished.

The explanation so far is that the amplitudes add back together as per complex addition. But then, "nudging" the photon at one point, eliminates the entire phenomenon involving combination and manipulation of (complex-valued) amplitudes? A nudging whose existence we can't even verify?

Why does the complex amplitude reality slip away upon thus nudge? Why can't I "explain away" any observation now by saying "ah, yeah man, there must have/not have been a nudge, problem solved".