This paper deals with social anthropologists serving as expert witnesses in asylum proceedings in the UK. It argues that it is not a fundamental epistemological divide, but rather massive power differentials that characterise the relationship between social anthropologists and legal practitioners in this context. Within a narrow framework provided by the law, which focuses on ‘true facts’ and ‘objective evidence’, social anthropologists have to position themselves, and they often must do so somewhere along a spectrum from positivist to post-positivist positions (regarding, for example, such concepts as ‘culture’ and ‘identity’). This, as well as their subordinate position in the context of the proceedings, sits uneasily with the professional, moral and ethical standards of their discipline. Engagement as an expert, therefore, comes with certain costs for social anthropologists that range from having to bend one's own epistemological perspective to the risk of being ‘demolished’ as an expert (and beyond) in sometimes implicitly politicised asylum decisions.