The vast literature on teacher professional development (PD) often assumes that the success of a PD programme should be measured by the extent to which the participating teachers accept and adopt, often in a relatively linear chain, the programme of learning, paying insufficient attention to how highly accomplished teachers respond to PD situations. This study investigated the experiences of a group of nine highly accomplished secondary school teachers, who also held leadership roles, following their participation in an intensive PD programme. Using an analytical lens of 'acceptance barriers,' we studied how these teachers interpreted their experiences of the programme and the impact of those experiences on their thinking and practice. Our findings show that teachers experienced the programme as a starting point, not a finished package. We identified a continuum of ways that these teachers applied, adapted and amplified ideas from the programme. We argue that recurring features of PD models such as linearity and implementation fidelity do not recognise teachers as professionals who assert agency over their own practice, and that the design, implementation and evaluation of PD programmes need to address how highly accomplished teachers are likely to respond, balancing fidelity with expectations of agency.