Someone sat shiva for several days believing his father had died, and then learned that his mother had died instead. Must the mourning count begin again?

This source-based Torah study examines the question: Someone sat shiva for several days believing his father had died, and then learned that his mother had died instead. Must the mourning count begin again? It follows the canonical Hebrew discussion through the weekly Torah portion and the Jewish sources cited there. This localized discovery layer is a concise abstract, not a full translation and not a practical ruling. Any halakhic, medical, legal, security, bereavement, political, mystical or other sensitive claim remains subject to the canonical review status and should not be treated as individualized advice or as an empirical conclusion.