I have never failed a student, but one did drop on request.
I have, however, advised a lot of students to take a different course than they first intended. A lot is done with aligned expectations.
Also, I have certified students to a lower level of certification than they enrolled for.
I feel that the core concepts in training is to teach with the end goal in mind so students won’t need to un/re-learn, develop taxonomy to the point where students are more aware than just capable of executing some skill very well (basic rote learning) but actually able to evaluate when it’s applicable (able to think), and application so students don’t end up mastering mask skills sitting in a pool - rather able to handle a mask swap hovering in open water.
There is a lot of fuss about “Mastery Level Training” going on these days, which is great for ensuring that a dog can sit or roll really, really well.
I overheard a talk at DEMA a few years ago about the merits of Scenario-Based Training.
I think a good question for the RSTC, if one is even bothered with their opinions, is how to best structure a progressive, linear, consistent training curriculum towards that arena.