The evaluation of teaching quality and practice is increasingly important in higher education and usually done via student surveys (quantitative data) alone. Much less attention is given to teachers' self-evaluations of teaching practice (qualitative data). This emphasis on quantitative over qualitative data can result in incomplete and biased measures of teaching quality, and inappropriate changes to educational practice, which may, in turn, negatively impact outcomes, experiences and university microcultures. In this paper, we present a case study of an international residential masters module, in rapid transition to online delivery during the COVID-19 pandemic, to demonstrate: 1) how developmental evaluation (DEval) can be used for rigorous critique of teaching practice in conjunction with student satisfaction data; and 2) how qualitative reflections on teaching practice can be transformed into justifiable evaluative evidence, using DEval theory and techniques. Our DEval approach, theorised and enacted using the community of inquiry framework, increased the teachers' skills and confidence to plan and continually evaluate teaching-learning enhancements. We discuss the implications and benefits of DEval for teachers and universities when used to assess teaching quality. In addition, we expand on existing knowledge to provide clarification on the purposes and appearances of all levels of evaluation in higher education.