On a flight from Asia to the US on British Airways recently, I missed the connection in London. The first flight was delayed because of mechanical reasons. London was chaotic and British Airways was quite rude and unresponsive but after a significant wait they agreed to put me up in a motel (quite seedy - particularly for someone travelling on business class). Since I could not access my checked-in bags I decided to pick up a set of undergarments from the airport. Am I allowed to charge these (which I think are very reasonable) to the airline. What am I allowed by law? (I have no clue what law applies).
EU passenger rights apply. If the delay was not caused by "extraordinary circumstances", you may be entitled to some monetary compensation.