My girlfriend just flew back from KUL for work. To get there and back, it was cheapest for her to buy two tickets: SFO-LAX-SIN on Delta (DL) and then SIN-KUL on Tiger Air (TR). On the return, TR made her check her bag, which then did not arrive at SIN. Because she had a connection to make, she got on the next flight back to the US without her bag. Obviously TR is solely responsible (these were two separate tickets).

The problem is, what are they responsible for? The bag has been located, but is at SIN now, and TR claims they are not responsible for sending it back to the US (since SIN was the destination on her ticket). Is this true? The Montreal Convention seems to apply, but there does not appear to be anything about these particular circumstances. Are they liable for all costs to get the bag home, given that their delay created this fiasco?

If they do not send the bag, I am not sure how we're going to get it back. Obviously flying back to SIN to get it is out of the question.