"It is always much easier to teach an aeromodeller to fly".
Try convincing one that his model does not loose airspeed on turning downwind, or gain it on turning upwind.
On this issue I'd remind them of the law, and that your instructor was flying legally (not below 500' above the runway), and their website appears to show evidence that
they do not fly legally. Point out the dangers of that and tell them if evidence comes to you that they are still acting illegally you will take it further.