Gordon Lightfoots song came first and it was a hit in the 70s in Europe. I wasn't with Bobby when he composed the lyrics and added the chorus. And indeed he did write other songs Mc Ilhaton and Marcella (dedicated to his sister) and numerous other poems and articles.

The serious question of being a Terrorist needs defined.
It seems that anyone who took up the struggle for Irish freedom has been labelled 'Terrorist' or helping Terrorism. As indeed was George Washington and his recruits in the 1700s.

The word Terrorist was invented by the British Government as an image creating word that is meant to Demonise those that oppose their rule.
The lyrics of another Irish Ballad give a good reply.

The ballad of Joe Mc Donnell - Comrade of Bobby Sands who also died on Hunger strike in 1981.

And you dare to call me a Terrorist, while you look down your gun.
when I think of all the deeds you have done
you have plundered many Nations, divided many lands, you have terrorised my people and ruled with an iron hand.
And you brought this reign of terror to my land.

Probably the most famous person to be labelled 'Terrorist' is Nelson Mandela.