What is the ruling on one who delays bowing with the Imam without a legitimate excuse, except to complete reciting Al-Fatihah?

The congregant should recite Al-Fatihah, and it does not harm him if the Imam rises from his bowing, and he is excused for lagging behind him due to a valid reason. Ibn Hazm said: "Whoever joins an Imam and begins reciting Umm Al-Quran (Al-Fatihah), and the Imam bows before he completes it, he should not bow until he finishes it; due to the obligation of reciting it in every bowing, and because of the Messenger of Allah’s (peace be upon him) saying: 'Whatever I precede you with when I bow, you will catch up with me when I rise.'"