Originally Posted by DeafFlyer
That stinks. Did the rules really change or was it just this one officer?
Can't be sure, but can speak from experience.
This weekend, Mrs c (US) and I (UK) flew into ORD and went through the US Citizens line with no problem. Noticed another couple (also US & UK) do the exact same thing in an adjacent line.
We had no difficulty using the EU line at LHR on our return, either.
That said, we make it our practice that whoever is a citizen of the country in question takes the lead, presenting the documents etc.