It definitely was Shorter. But I know he was heavily influenced by Jack Bacheler, though that wasn't coaching. I remember reading some comments by Roy Benson who was assistant coach for he Florida Track Club then about what he did as "coach" to Shorter. He said something along the lines of, "If they needed a towell I'd get them one.
Most runners I knew, when they reached a certain level of maturity, were very skeptical of coaches and I would say they were wise to be so.
Study/work with the best coaches and fellow athletes you can and ultimately you make your own decisions based on your current experience and knowledge.
Sometimes there is close consultation with a coach sometimes not.