Jon, I am glad that you had a good lesson with someone from PSIA. You probably would with me as well. I will tell you that recently I had the opposite experience.
I took a recertification clinic to keep my PSIA level III cert current. The clinician leader, a member of the education comittee tore me appart for my known fondness of direct to parallel methods and known leanings towards HH.
He had me demo some direct to parallel stuff. In each case he would ride a stance ski and tip the free foot while running a straight line right across the slope. He used his ability to do what I had said while running an intentional straight line across the slope as proof that direct parallel methods were biomechanically flawed and did not guarantee a student would learn to turn. In addition he said that pulling back the inside foot guaranteed divergence and the inside hip dropping back in every turn.
He then showed his interpetation of pathways to parallel. His first move was from a straight glide to steer the stance ski around the inside ski big toe edge that produced a straight inside ski and wedged outside ski ahead of the inside ski. He then said do the same thing only keep the inside tip even with the outside tip. On easy terrain this definitely produced a nice turn with the inside hip forward that I could not deny. His next move was release from a traverse. He squared up the tips and brought the uphill hip across the skis towards the new inside ski tip. This produced a very nice release. He then took it into a garland and finally into an open parallel turn. His nice open parallel turn had no wedge, was nicely spaced in a fairly wide stance and produced a nicely skidded turn. It also clearly showed rotation of the new outside hip and upper body to start the turn. This is also precisely what he taught.
My comments were that yes this produced a very nice looking turn but that rotation is the only method that guarantees a turn without intent. The difference he showed was not that direct parallel was fundementally flawed but that what it showed was his intent not to produce a turn and rotate the hip back. This is something that is key in direct to parallel. We don't have to teach something that is going to happen as a natural result of intent. That is like teaching someone to breath.
I used his method to illustrate the opposite. Since I could not help but turn with his method and he could intentionally not turn with mine I used it as proof that rotation produces unintended turning forces that cannot be controlled precisely because intent had no effect on stopping the turn. I said that both of us produced beautiful nice turns but that we had the bag of tricks to make it all happen already that that his pathway took a long time to learn to control the unintended turning forces.
He insisted that moving the new outside hip forward and across was not rotation but proper release of the skis that results in a turn in the correct direction due to the CM being moved down hill.
He parted with asking if I had learned something an understood much better the mechanics behind good skiing. I answered yes, very definitely and it was true.
In the past I have been very critical of Harald's interpretation of current PSIA thinking but I have to tell you I was having a very difficult time hanging onto that idea in this clinic.