As mentioned here in the discussion, ideas, techniques and methods can not have a copyright but someone's actual description or words can be. Also if a technique/method is an 'original' process it could be patented to prevent any infringement of 'ownership rights'. This usually occurs in different industrial arenas.
That said, I think that in this situation that has been presented, it is a case of 'common sense'.
Last year, I took a class on a technique that has been around as long as quilters have been sewing. Although I have been sewing for over 50 years and feel that I have a high level of experience, I had never done this technique before and thought that this class would be an easy way to learn any short cuts or tips on the method. Along with the class fee, a $30 book from a specific author was a 'required' purchase in order to take the class. Signing up, I didn't have a problem with this but realized by the end of the class that the 'required' book had not been referred to at all during the class and was of no particular use after the class. The LQS may have thought that they were covering their 'integrity' and their butt by requiring that this book be purchased but it was a complete waste of money and I will never take another class again at this particular LQS!!