A fine example is provided by
Jacques, V.; Wu, E.; Grosshans, F.; Treussart, F.; Grangier, P.; Aspect, A. & Roch, J. Experimental realization of Wheeler's delayed-choice gedanken experiment. Science, 2007, 315, 966-968
Let me just quote here the conclusions of the paper:
Our realization of Wheeler’s delayed choice Gedanken Experiment demonstrates beyond any doubt that the behavior of the photon in the interferometer depends on the choice of the observable which is measured, even when that choice is made at a position and a time such that it is separated from the entrance of the photon in the interferometer by a space-like interval. In Wheeler’s words, since no signal traveling at a velocity less than that of light can connect these two events, “we have a strange inversion of the normal order of time. We, now, by moving the mirror in or out have an unavoidable effect on what we have a right to say about the already past history of that photon”. Once more, we find that Nature behaves in agreement with the predictions of Quantum Mechanics even in surprising situations where a tension with Relativity seems to. appear
I wonder if this result will hold on repetitions. If yes, then this would reaffirm that we have a lot to understand yet. Especially about time in Quantum Mechanics.