Is it correct what the worshippers did who prayed with the one who stepped forward to lead the prayer after the electricity cut off, or what was done by those who left to search for another mosque?

A fatwa was previously issued under number: 109733. He who came forward to lead the prayer, but was not the appointed Imam, erred. The congregants also erred by leaving the mosque. They should have tried to follow the original Imam by descending to the first floor or praying in a nearby place where they could hear the Imam and see the worshippers. As for someone who caught the Friday prayer in another location, that suffices him. However, whoever prayed the Friday prayer behind another imam, his prayer is not valid and he must repeat it as Dhuhr.