A major challenge faced in research seeking to investigate the underlying dynamics of problematic interactions is that, when asked about the rationale underpinning what they said and did--their "theory of action in-use" (Argyris and Schön, 1974, 1978, 1996)--participants are often unaware of what prompts their behaviour--or decide to hide it--so instead produce their "espoused theory of action", the rationale they think ought to have been underpinning what they said and did. Using the left-right case protocol (Argyris and Schön, 1974), researchers investigating problematic interactions, especially interactions open to different cultural interpretations, are able to identify points of dilemma in these moments when participants report thinking X, then self-censoring and actually saying Y. The question "What prevented you from saying X?" allows the opening up of participants' theory of action in-use--where they thought they were, what they thought was happening, and what they thought their options were. This access to their theory of action in-use could then be opened up and examined with the participants. This paper will present the attributes of the protocol and its rationale, and give examples of its effectiveness in the study of Chinese-Australian problematic social interactions at work.