Patient and public involvement in health research is increasingly well established internationally, but the impacts of involvement on the research process are hard to evaluate. We describe a process of qualitative data analysis in a mental health research project with a high level of mental health service user and carer involvement, and reflect critically on how we produced our findings. Team members not from research backgrounds sometimes challenged academic conventions, leading to complex findings that would otherwise have been missing. An essential component of how we coproduced knowledge involved retaining methodological flexibility so that nonconventional research voices in the team could situate and critique what was conventionally known. Deliberate and transparent reflection on how "who we are" informed the knowledge we produced was integral to our inquiry. We conclude that reflecting on knowledge (co)production is a useful tool for evaluating the impact of patient and public involvement on health research.