Facilitators of teacher professional development (PD) courses mediate the course ideas conceptualized by the PD course designers. It is relevant to research what views facilitators hold in reference to the content goals, the learning obstacles, and the teaching resources that constitute the heart of a PD course. In our current study, we analyze one facilitator's deliberations in an interview conducted after a PD day on conditional probability, based on a framework of expertise on the classroom and the PD level. The results reveal which elements of the PD course were adopted wholeheartedly, and which remained more or less superficial. The analysis also suggests reasons for this distinction and how to rethink facilitator qualification and PD course material.