Not the same thing.
If my memory serves, the Guardsmen thought they were being fired on.
I am a Army vet.
Just looked it up. Seems there was someone there with a pistol. http://www.cleveland.com/science/index.ssf/2010/10/analysis_of_kent_state_audio_t.html
But they weren't. They fired into the crowd indiscriminately.
The National Guard requires its members take an oath saying that they will defend the Constitution against all enemies, foreign and domestic. The Constitution gives Congress the power to call up the militia to execute the laws of the union and to suppress rebellion. If the National Guardsman isn't willing to do their duty as soldiers under the Constitution then maybe they shouldn't be National Guardsmen?