For most of the time since the Comet V's arrived on the scene, more often than not, you would see solid sets of MTA equipment with either a geep of F40 leading the MTA equipment. Since the PTC fiasco, NJT seems to be mixing equipment all over with more NJT equipment going to Port Jervis all the time. Granted I'm not out there watching every train, but the only F40 I have seen recently has been sandwiched between another cab car in front. Most other trains to Port Jervis have NJT power regularly now
I think it may be possible that NJ Transit might not be the perfect, infallible organization that most people assume it is.