Sounds flaky. These are 'no jerking, spanking' people, and I wouldn't trust them to teach a dog to sit-stay reliably. Clicker-trainer people can be trusted with Goldens and Labradors and Shelties that are good out of the box. Corrective training means being able to enforce "no".
I have a supervisor at work that has trained all of her dogs this way. She also rescues dogs. She has four, two of which come to work every day and stay in her car because they fight with the other dogs. None of them will sit or come without being told several times. They would not last long at my house.
How many aggressive dogs have you successfully rehabilitated? This dog has been "trained" in Schutzhund, by a person without much experience. Do you know how a dog with a dominant personality, or worse a fearful dog, will react when subjected to harsh training methods, particularly when one family member is "harsh" (as stated on this thread), and one family member is permissive? They will escalate aggression. This dog is going to hurt someone, soon.
Have you ever heard of the "Nothing In Life Is Free" training method? The trainers on the board I mentioned, who have plenty of experience successfully rehabilitating dogs with aggression problems, use this method. It works FAR better than hanging a dog 'til it is near death like some of the Schutzhund macho jerks suggest.
This dog's very life depends on the owner getting a handle on his potentially dangerous behavior. I am familiar with the methods used by the trainers on AGBEH, and they work (and I have a few years of training experience, around 35 or thereabouts) if followed correctly.