A man came to the Prophet (salallhu alayhi wa sallam) from Al-Yamamah, learned some Quran, and apostated and joined Musalimah. His kunya (pet-name) was Ar-Rajal (“the man”). He endorsed Musaylimah.
His fitna was more intense then Musaylimah. People thought he was learned and scholarly, and he believed in Musaylimah. It caused a huge doubt among the ignorant people. They felt that if Ar-Rajal listened, they should listen, too.
Today, everyone has endorsements. You need to learn to see beyond the endorsements. If the whole world says it’s haram, and this one shaykh says it’s ok, he endorses it, it causes mass confusion.
References
Muhammad Alshareef. Lecture. AlMaghrib. Conquest: History of the Khulafa. University of Toronto, Toronto. November 2005.