A fall arrest system or harness would not have been much use on this type of structure and would possibly only cause an accident. If he fell with a harness on him who is gonna pull him back up? Where is he gonna clip his lanyard onto on an old building like this, theres not gonna be any latch on points. A cherry picker would hardly be viable, permits, cost etc. This guy is old school, he knows what he's doing instinctively, its the way those windows have always been done. The difference now is every do gooder now has a smartfone.