Alger Hiss was slam dunk guilty, all but caught in flagrante delicto. That didn't stop his friends and allies from defending him for decades. Same with the Rosenbergs, the people who slimed Elizabeth Bently, Joe McCarthy ... how long do you want me to go on?
Paul Ehrlich lost a bet for $10,000 to an economist who told him his claims of an upcoming population calamity (in the 1970's) and the attendant shortages were bunk. Still has not surrendered one dollar.