Extracts from the press release on the bmi website, and
my suggested 
translation:
"This uncertainty is also impacting upon our ability confidently to sell seats from Heathrow to Mumbai. The marketplace is intensely competitive and we have serious concerns about a prolonged period of over three month’s absence. A sustained absence will place us at a considerable disadvantage against the competition that we face on services to Mumbai when we are able to recommence operations."
("We don't know when the aircraft will be back. We're arguing with Airbus about this and claiming for consequential damages, so our rhetoric has to demonstrate that we're suffering a major loss, but whenever we do get the plane back, we'd virtually have to relaunch completely in the Mumbai market, and we're not sure it's worth our while.")
“This is only a temporary setback to our long haul route network growth and we remain committed to the development of that part of our business. That is why we have made no reductions in operating crew levels including the 66 cabin staff positions involved in the Mumbai operation. Any job losses will be minimal and all confined to India based positions.”
("We know we will get the plane back sooner or later and we can find other things to do with it. The 66 cabin staff will be needed whether the plane's going to Mumbai or somewhere else. We're letting go of some or all of our people in India, which may suggest that we're preparing to exit the Indian market. There's more and more competition in the UK-India market, it's not working out as well as we'd like, and if we can extricate ourselves from that market and get Airbus to eat some of the blame and the costs, so much the better.")
Note that the last sentence is complete speculation on my part. But clearly LHR-BOM has been the least well-performing and/or least-strategic of the daily/near-daily BD long-haul routes - why else would it be the one they canned when they lost an aircraft?
C.