Didn't know of this song, just had a listen to it on youtube. With all due respect to the great Gene MacLellan - the Donnelly clan is right; it's quite defamatory. It repeats the exaggerations, if not lies, that were encouraged by the murderers and their families, to justify what they did. I'm sure MacLellan just figured it was a good story. Which it is.

The Donnellys were undoubtedly a rough and violent bunch - but they weren't the only ones.

Btw, I went to school with some kids who were somehow descended from the Donnellys - they never talked about that, one way or the other, except that one of them mentioned it to me in passing - but that perhaps made the whole business a little more 'real' to me.