As part of neoliberal reforms, evidence-based practice is increasingly influencing teachers' work. In Norway, the American programme 'School-Wide Positive Behavioural Intervention and Support' (SW_PBIS) has been implemented in a great number of schools. One school experienced an intense conflict with parents, so that eventually it opted out of the programme. Using Basil Bernstein's framework, this paper investigates what the conflict was about and how it can relate to class and ideology. The conflict was rooted in the ideological foundation of the programme, as well as its unintended negative effects. The teachers' unexpectedly persistent support of the programme may be explained by the fact that it offers them a way out of taking personal responsibility for a pedagogically challenging situation. Looking into the role the specific contexts play may contribute to a deeper understanding of the complex relationship between class, values and practices as teachers' hierarchical relations may be changing.