What is the ruling on intentionally not completing a word from Al-Fatiha in order to follow the imam in rukoo‘ (bowing), and is that considered a clear mistake (laḥn jalī)?

The preferred view is that the follower (ma'mum) must complete reading Al-Fatiha even if the Imam bows before the follower finishes it. If the follower bows before completing it, we hope that there is no need for him to repeat the prayer. However, if the follower intentionally omits a letter from Al-Fatiha in order to catch up with the Imam, his prayer is invalid if he were praying alone. But we hope that he does not need to repeat it, out of consideration for the view of those who do not deem reading (Al-Fatiha) obligatory for the follower.