Originally Posted by
Tobias-UK
Correct. When the OP checked in for his flight his passport information would have been provided demonstrating there was a valid travel document that entitled him to make the journey. At boarding the OP used his EU ID Card to prove identity.
That is the bit I missed... especially as passport info is preloaded in BAEC system most of the time, so one could very easily just confirm it without ever bothering to notice it was sitting on an embassy desk.
At boarding he provided a card that wasn't valid for travel (he'd already given that electronically), but did verify his identity... I can see how it can get blurry.