Much like the episode where Michael Westen meets the real-life actor Michael Weston, in this one he assumes the identity of "Micheal McBride." One of the Irish thugs is played by Michael McBride.
All three of the named Irish characters (Fiona, Sean, and O'Neill) are played by actors born in England.
The episode's bad guy is named Thomas O'Neill. Presumably not by coincidence, the writer of the episode, Craig (S.) O'Neill, has the same last name.