As the event lasted only 4 hours, does that mean it would have had different levels of effect on different regions of the planet? Countries on the far side would be better shielded.
If it hit the earth it would have slowed down and stayed longer.
The charged particles interacting with the magnetic field of the earth would have produced a planet wide EMP (larger than even a nuke could do). The charged particles would have induced electric current in any large wire and would have acted on the whole planet.
It took only 4 hours to get from the Sun to Earth, but then it 'slows down' and hangs about?
I was thinking of the 1989 CME, which had localised effects in Canada. But that was much smaller