What is the ruling on the latecomer (masbuq) in prayer, and does his ruling differ among the jurisprudential schools of thought, such as the Maliki and Shafi'i schools?

Scholars have differed regarding what a latecomer (masbuq) catches up with his imam in prayer: should he consider it the beginning of his prayer and build upon it, or should he consider it the end of his prayer and make up the beginning of his prayer? Imam Al-Shafi'i adopted the first view, while Abu Hanifa and Ahmad adopted the second, and Malik combined both opinions. The reason for this difference in opinion stems from the varying narrations of the hadith, specifically between "fa'atimmu" (then complete) and "faqdu" (then make up). "Fa'atimmu" implies that what one catches up with is the beginning of his prayer, whereas "faqdu" implies that it is the end of his prayer. The preponderant view is to act upon the narration "fa'atimmu," and that "faqdu" means to complete. This issue is a matter of ijtihad (independent juristic reasoning), and it is not permissible to condemn someone who holds a different opinion. A Muslim should follow what appears to him to be closest to the Sunnah if he is qualified for ijtihad; otherwise, he should follow someone he trusts or the madhhab (school of thought) of his country.