Complex sentence: It is also worth mentioning that these men had not felt contaminated by the actions of disgraced former IRA Chief of Staff Stephen Hayes, the "Hayes Affair" being an episode widely seen as damaging moral within the IRA.
Split into simpler sentences: It is also worth mentioning that these men had not felt contaminated by the actions of disgraced former IRA Chief of Staff Stephen Hayes. The Hayes Affair being an episode widely seen as damaging moral within the IRA.