Sorry to hear about your ordeal - I've never known them to check how a ticket has been paid for! You simply give your ticket and your passport, and that's it!! My friends flew back to UK recently as well, on Emirates though via Dubai, and they had no issue of having to show the credit card they bought their tickets with ... That's insane, I'm sure it's last thing you need when you're flying back to get married! I don't know what I'd do.