why they asked you for an ID card is bizarre...although I have to say I had a similar experience that was even more Kafkaesque... I have an EU passport (Italian) and I live in France. When I tried to board in BOS-CDG on DL I was told I needed a residency permit or else I couldn't board. I actually had to pull up a screen from the French government saying that they no longer issue ID cards to EU nationals unless requested... I almost missed my flight because of this one bozo.