It is a little bit more complicated. Since
LeisureFirst is officially 'home' BA does not have to pay for replacements (unless the bags are truly lost). Travel insurance will not pay for anything either (again, unless the bags are truly lost) because the trip has ended.
Chalk it up to experience and if you travel with stuff that is so important you will cancel trips for it, bring it on board.
By the way, not one of the best of trips now, is it?
