A friend of mine is a lineman, last year they changed out towers along Rt.190 in Sterling MA. They changed all the towers "live", 345,000 volts without a hitch.
I'd try the live line work tomorrow with the right training. One thing about electricity is that if you follow the theory it works the way it's supposed too. I've also read that those guys can only work on the lines for a limited amount of time due the the massive EMF(electro magnetic force) surrounding them, seems that you get tired quicker, of course no watches, jewel etc.
I also have a healthy respect for it, a few years ago I had a 4000amp substation blow up with me in the room with it. Sounded like a shot gun being fired over and over until the power from the street finally shut down. Completely vaporized the copper buss bar, multiple 6" wide 1/4" thick layers.
I've also done a fair amount of low voltage live work, 480v and lower. I changed out a pair of 3 phase transformers live with special jumper cables I made up, customer "couldn't" let me shut down the research lab he was working in. As long as you follow the theory it works.
Great video, thanks for posting,
Ed
PS. Thanks Dave!