TL;DR: British Airways caused me to miss a connecting flight with Aer Lingus. Who do I claim compensation from?
I had a flight from Rio de Janeiro (GIG) to London Heathrow with British Airways, and a connecting flight to Shannon with Aer Lingus - they were booked on a single reservation.
Although the BA flight landed on time (slightly ahead of schedule actually), it was forced to wait on the tarmac as its docking station was in use, and as a result we disembarked late. Despite this, we quickly made our way through security and to the other terminal from where the Aer Lingus flight was to take off.
At this point, however, our boarding passes were denied. We were told to step aside and wait while everyone else boarded the plane. Then we were informed that because of the afforementioned delay, British Airways had cancelled our boarding passes, and we no longer had seats.
I'll skip all the activity in between, but eventually, the agent at the BA desk confirmed that someone in BA had indeed cancelled our tickets and we had been rebooked to the next day.
Because of this, we are supposedly entitled to compensation of either €250, €400 or €600 per passenger. (Depends on the distance of the flight but I'm not sure if it's just the missed connecting flight or the entire journey that's considered).
But my real question is, who is liable for this? British Airways or Aer Lingus?
Since the delay and the mistake was on the part of British Airways, I would have expected it to be them. However after contacting them, they refused the claim since they didn't operate EI385 (the Aer Lingus flight), and said I should claim the compensation from them. I will contact Aer Lingus, but I have a feeling they will just send me back to British Airways (the people at the boarding gate were adamant that the fault was with BA)