Why were Nadab and Abihu punished for ruling in the presence of their teacher if one may issue a ruling in order to prevent a transgression?

This source-based Torah study examines the question: Why were Nadab and Abihu punished for ruling in the presence of their teacher if one may issue a ruling in order to prevent a transgression? The canonical Hebrew article develops the issue through the weekly Torah portion and the sources cited there. This localized discovery layer preserves the question and the source identity; it does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.