What is the Shar'i ruling regarding a traveler who combined and shortened the Dhuhr and Asr prayers, then led residents in the Asr prayer, claiming that it would be counted for him as a supererogatory prayer?

Scholars differed regarding the time of prohibition for prayer after Asr. The majority absolutely forbid it. According to the majority opinion, absolute voluntary prayer is not permissible after the Asr prayer, and the worshipper's initiation of it is invalid. However, for one who prayed behind an Imam whose condition they were unaware of, their prayer is valid, as there was no negligence on their part.