Thats strange, It was reported in BM thats all that was done on the Hopkins vs Taylor II bill was ringwalk - no actual fight scene. I am amazed that there is no spoilers about. Although, I think I can guess what happens.
They didn't film the fight scenes there that night. They would have have been filmed afterwards either there or in another gym or studio with a small number of people around the ring with the remainder blacked out.
