[[WMG: The IRA helped Gerry to fake his death and give him a new identity.]]
Henessey promised to speak the the high command on his behalf for a favour. It's highly plausible that they rescued Gerry from the water somewhere further up the coast, gave him new papers and helped him slip away.
[[WMG: The kid on the bike is death.]]
He's always around when bodies show up.
* He mentions [[GunmanWithThreeNames John Wilkes Booth]] using a derringer to kill UsefulNotes/AbrahamLincoln. [[FridgeBrilliance If he's Death, then he was there.]]