First of all, since we have a reputable article from 1920, we need to consider what it says here before we make judgment.
But the second issue is whether or not the prisoners in the specific issue at hand were justly imprisoned. I don't know enough about the Irish Republican Army of the 1980s except to say that I've read that they were essentially communists rather than true Irish patriots. Is that true? I don't know.
If the IRA was, in those days, more of a communist front, then I would not place too much stock in the morality of their actions. If this is simply English propaganda (which is a very good possibility) then their actions could have been meritorious.
Frankly, I have always doubted the "official news" out of Northern Ireland. The English really don't have a good track record on respecting the rights of Catholics. On the other hand, many of the apparent targets of the IRA have not been what true freedom fighters would be targeting. But then again, I had never heard of "fαℓѕє fℓαg operations" back then, either.
I just don't know about this particular case.