My friend clarified it. Here's the message:
it was sold in 2007 and then became Caribbean Airlines - but they never even bothered to change their flight numbers so they still show up as BW....I'm not holding up much hope for its return - its just a matter of fighting for the reimbursement. As XXX said - according to the Montreal Convention we should be able to claim for the max amount....fingers crossed.
Anyone has any idea how to find it? You think the bag may be stolen?