What is the manner of praying behind an Imam with whom one catches the opening takbeer but not the rukoo‘ for one who recites Surah Al-Fatiha?

Whoever among the congregants is unable to recite Al-Fatihah, or fears missing the bowing with the Imam, should bow with the Imam even if he misses Al-Fatihah. This is supported by the hadith of Abu Bakrah, who bowed before reaching the صف (row), and the Prophet, peace and blessings be upon him, did not order him to repeat the rak'ah.