The Horizon 2020 framework programme for research and innovation is promoting an approach referred to as Responsible Research and Innovation (RRI). Mandates to implement and mainstream RRI are already evident, whereby interdisciplinarity and integration are treated as pre-given in accounts of what the RRI approach is in practice. In this paper, our point of departure is to ask what to expect realistically when experts and professionals are brought together across disciplines, institutions and national borders in practical attempts to achieve interdisciplinarity and integration of approach to innovation. We revisit Woolgar's and Ashmore's treatise on social epistemology in their development of the reflexive thesis in the late 1980s, and we revisit the turn to practice in STS in the early 2000s. We present our analysis of commitment to matters of practical sensitivity and reflexivity in reference to the philosophical influences and study objectives of the reflexive thesis and the practice turn and we consider how sociological studies have articulated expert practices and the use of knowledge and skill. We address the epistemological challenges innovation assessments face in justifying the relationship they draw between study objects, observation, interpretation and representation and in justifying ideologically and methodologically their own production of knowledge about how others produce knowledge. We address the implications this work has for the development of interdisciplinarity and integration in case studies we have observed, of evaluating new-emerging innovation domains. We argue that the consequences of advancing reflexivity (or awareness of it) as a progressive step forward, rather than a problem to remedy, is critical in shaping a more balanced approach to innovation, even though achieving interdisciplinarity and integration is fragmented and partial.