zurückrudern — To row back. DWDS gives the figurative meaning: to withdraw a measure that met with rejection, or to take back an opinion or position. Its example: Wird die öffentliche Empörung zu heftig, rudert die Partei zurück. If public outrage grows too strong, the party rows back.
eine Rolle rückwärts machen — To do a backward roll. DWDS: to take back something one had announced or promised.
umfallen — To fall over. DWDS lists the figurative meaning seine Meinung, Gesinnung überraschend ändern, to change one’s opinion or conviction suddenly, and marks it as disparaging.
der Umfaller — The one who falls over. Duden marks the word as colloquial and disparaging.