While I really enjoy case discussions, they don't always work well. The variance in class quality is far larger than lecture-based classes. In my experience, this is because the case method requires students to be selfless while they are also being graded.
In its ideal form, students should only speak when they have an opinion on how the protagonist behaved or if they have been cold called. But, because professors grade students on class participation, many students feel a need to ensure a baseline quantity of comments even if it comes at the expense of quality. This means that class can devolve into a discussion of case facts.
While laying out the facts of the case is necessary for everyone to be speaking the same language, facts should only be used as evidence, not as the crux of a comment.