Shamrock 125, ORD flights generally use more northerly tracks than flights to BOS or JFK. You are quite right that LAX flights normally depart via GELKI and BEL. However, a reasonably typical departure for ORD from DUB would route via ERNAN, entering UK airspace at that point. Most UK airspace is, as you correctly state, to the east of DUB but there is a considerable amount of it to the north and northwest as well.