Professor Galloway might be advised to also get his shit together and/or remove the stick from his ass. Rather than say: "This is a suboptimal situation, how can we fix it?", he simply called the student immature and disrespectful, and never acknowledged the possibility that he, or some institution he has influence over, might be partially at fault in the matter.

Masters/professional degrees are hardly an "academic pursuit". Universities treat them as a profit-generating device, and as such, it's reasonable that the customer be able to make an informed decision. In relatively short professional-degree programs, you will often have only one chance to take a given elective during your time there. Sometimes you have to make a decision between these courses. In my Masters program, I made the wrong decision regarding electives more than once, missed out on some very interesting courses, and wasted my time with some absolutely lousy ones.

In an ideal world, the school would provide some reasonable solution for this. Either by having some reasonable culture of course-sampling, or if they feel that harmful, offer videos that allow students to, on their own time, sample the course and make an informed decision as to whether the course is worth their limited resources.