It's quite interesting that they also attacked a substation that looked important on a map, but wasn't actually vital. I think some of the early reporting about this incident suggested they "knew what they were doing", but the apparent misidentification of one of their targets perhaps suggests the perpetrators were making educated guesses, without detailed/insider knowledge of how the system worked.
2. Nothing discussed in the video is insider knowledge. Everything is public knowledge, and could have been learned with a library card and an internet connection.