Should a latecomer to prayer who joins the Imam while he is standing, shortly before bowing, delay behind the Imam to complete the recitation of Al-Fatiha, or does the remainder of Al-Fatiha become waived for him if the Imam bows before he completes it? What is the Shafi'i madhab regarding this issue? Does the ruling differ between a silent and an audible prayer? And what is the most authoritative opinion among your conflicting fatwas on this matter?

Both fatwas are correct. According to the Shafi'i school, the congregant (ma'mum) is either a latecomer (masbuq) who did not catch the time of reciting Al-Fatiha, in which case he must bow (ruku') and Al-Fatiha is waived for him; or he is an earlycomer (muwafiq) who caught the time of reciting Al-Fatiha. If his imam bows before he completes his Fatiha, he completes it and catches the rak'ah by bowing. There is no contradiction between the two fatwas, as each pertains to a different situation.