The equipment necessary for generating versus detecting neutrinos is vastly different (and entirely immobile, to all intents and purposes). Calling half time a

The equipment necessary for generating versus detecting neutrinos is vastly different (and entirely immobile, to all intents and purposes). Calling half time and changing ends is a nice idea, but utterly impractical. Finding/building an alternative neutrino source and pointing it at the detector is (I think) the best approach to reproducibility, but it still leaves open the possibility of systematic errors in the detection mechanism causing the same issues. A different distance should give a different delay though, which would be one test. Another might be to try and use photons as a reference/synchronisation mechanism, but that's hindered by the fact that everything is in underground caverns.