Actually, I think I understand why he's wearing gloves and I think it is safe. First, they are thin, tight gloves that still provide good tactile control. Second, he is cutting materials that likely send off hot "sawdust" of metallic particles that would easily burn bare skin. When they change the blade to the diamond embedded one, then he removes the gloves and cuts a blue tile while holding it with bare hands. That is his dangerous move -- I would prefer to see the tile clamped in place against the fence.