No way.
You can be skeptical all you want, but the story is available from multiple sources and no utility is denying it.
See post 18 this thread.
By the way this isn’t the first time.
Cyber security
Hacking group Anonymous could shut down the entire U.S. power grid, head of national security warns
They get into classified dept of defense systems. Are utility systems more secure?
Not the ones I’ve seen and I run a security company.
If you are in ANY way connected to the internet - that is not a statement you can make with absolute certainty.