That is truly a bad scene.
We own a sign company and from the looks of the set up, it appears the driver or operator could be at fault because they could have set the truck up in another position to stay clear of those lines or he was clear and rotated the ladder/boom while not paying attention to the lines around him.
If you look close at the second image, you can see the ladder/boom is in between 2 separate lines. I think he just forgot his surrounds and got stung.
We always set up away from the lines, at least 20' and if that is not possible, then we rent a bucket lift. From the looks of all those lines, I would have rented the lift.
Condolences to his family.