This paper aims to critique the process of corporate-owned, high-tech start-up strategizing through an inductive, longitudinal, case-study of 'UK-Research-Tech'. Insights are given through the combined 'dialectical-paradox' concept, thereby focusing on where 'dialectic' and 'paradox' theorising overlap. Our linked iterative, 'dialogical-dialectic' research approach also reflects CEO/TMT start-up dynamics over time. These foci fill important gaps that impede our better understanding of dialectical, dialogical and paradoxical forces within strategic decision-making. As an interpretative tool, they illuminate CEO/TMT strategizing and changing inter-relationships, affected by broader, volatile, techno-economic contexts, and parent-company influences on ventures. In this case-study, it was found that the CEO's relatively autocratic, parent-framed approach combined with TMT members' contradictory reactions to create 'dialectical-paradox' oppositional forces, eventually only resolved through 'eleventh hour' business strategy changes to rescue the venture. This research contributes to more nuanced understandings of corporate-constrained ventures during early business development from start-up strategic decisions at parent-company level to subsequent conditions of more independent dynamic equilibrium. The 'dialectical-paradox' conceptual lens contributes an innovative critique of processes affecting strategic decision-making dynamics. Another important contribution is the empirically-inspired conceptual model, developed for use both to guide subsequent case-study research analyses and as a reflective tool for CEO/TMT strategic decision-making, especially within corporate inspired start-ups.