Stodolsky's Theorem and Neutrino Oscillation Phases -- for pedestrians
  Neutrino oscillations are experimentally observable only as a result of interference between neutrino states with different masses and THE SAME ENERGY. All interference effects between neutrino states having different energies are destroyed by the intereaction between the incident neutrino and the neutrino detector. Erroneous results are frequently obtained by neglecting the neutrino-detector interactions. 
Harry J. Lipkin (Weizmann Institute, Tel Aviv University, Argonne)