Ah, but he can only be referring to the behaviour of neutrinos in the Standard Model. What about the fabled fourth neutrino (and equivalent fourth antimatter neutrino) that may, or may not, exist? That/They could/could not be up to all sorts of roguery and rascality (though not breeding, of course, their being/not being sterile). FermiLab need to pull their finger out and get on with LBNF so we can/cannot discovering it/them – or not.