The problem with case studies is that PMBoK is not a guide how to run a project. In contrast to a methodology like PRINCE2. It is a guide to the PM knowledge and you would not want to apply all PM knowledge to one project or case study.
PMBoK is a guide to all the project management knowledge out there on the globe and gives it a structure (knowledge areas and process groups). It was created and is updated every 4 years by volunteers from around the world and strives to include knowledge that is used 'by most projects most of the time'. For any given project, there will be useful parts and parts you would not use. If you want to apply it, you have to tailor it - to your organization and to your project. Any case study will include the outcome of this tailoring.