What should a latecomer do who missed one rak'ah in a four-rak'ah prayer, then caught up with the Imam for four rak'ahs, with the Imam having prayed five rak'ahs? Should he perform the missed rak'ah?

The jurists differed regarding whether a latecomer (masbuq) should count the extra rak'ah performed by the Imam. The more accurate view is that it should not be counted, because making up what was missed (qada') occurs after the salutation (taslim). Therefore, the worshipper (ma'mum) must perform everything he missed after his Imam's salutation.