Has that ever happened though? Instructors have been doing workshops for quite a while. Just because I'm not aware of any litigation doesn't mean it hasn't occurred.That sounds great--it really does.
About a dozen years ago some friends and I started doing something similar, but one of them was advised not to do that by an attorney. The attorney explained that if something went wrong on the dive, there would almost certainly be a lawsuit, and in that lawsuit, the plaintiff's attorney would do everything possible to prove that what you did in that class was not within normal best practices for scuba instruction, and the burden of proof would be on you to prove that the instructional practice you invented was safe. If, on the other hand, the content of your instruction was already approved by a major scuba agency, the burden would be on the plaintiff to prove that the major scuba agency was wrong in approving the content of the course.
This is a similar stance as keeping insurance for non teaching status for 7 years after one stops teaching. Has an inactive instructor been sued?
Sounds like legal risk management.