In fact the SNN and DUB US imm thing is a pre-immigration clearance and is only for USA bound flights; this saves an amazing amount of hassle at the other end
unless you're going to the US you won't see them; all in all a good thing.
However, since if you're coming in on Ryanair you arrive at Terminal B .. no matter where you're coming from you'll end up mixed up with everyone else heading for Immigration ...
He must have done something to annoy the Irish immig lads on the desks...