Large-class university lectures remain commonplace, yet their educational value is contested. While the majority of criticism contrasts transmissive lectures with active learning pedagogies, this case study evaluates a lecture series on its intrinsic qualities, looking at staff and student understandings of the lecture's contribution to academic outcomes and the affect attendance has on students' study habits. The study took place within a health sciences module at a UK university. Data sources included lecture observations, interviews, focus groups, a survey, and institutional documentation. The conceptual framework used in the analysis is Snyder's "Hidden Curriculum," in which the formal curriculum of knowledge creation, is undermined by implicit expectations which foster instrumental learning behaviours. The findings indicate that the low demands placed on staff and students in transmissive lectures encourage an 'illusion of attendance' -- in which assumptions of learning from, and physical attendance at, large-class lectures are greater than empirical data evidence.