One thing to be noted: The film paints an inaccurate picture of 'practical' Irish neutrality. Ireland repatriated almost all Allied airmen immediately. They were basically given a cup of tea [edit: and probably a feast of pints too] and a bed for the night, and then put on the morning train to Belfast. My dad told me about it.

Though I have no evidence, my gut instinct tells me that those that stayed (RAF, I mean) were simply reluctant to return to the war. Most would have been bomber crew, and that job truly sucked. The attrition rate was really horrendous.

Wiki says: "Luftwaffe pilots who crash-landed in Ireland and German sailors were interned, Royal Air Force (RAF), Royal Canadian Air Force (RCAF), and United States Army Air Forces (USAAF) pilots who crashed were usually allowed to cross the border into British territory (although some Allied personnel were also interned).