For the lightning strike, which I think you meant was on LHR-SEA, then I would expect BA to provide an alternative aircraft at its home base. For the ORD-LHR service - it would be very unusual if the flight deck gave zero explanation before departure (in umpteen years flying BA it's never happened to me). And at this point it's too difficult to tell what happened, the records on this event will no longer be available. But for both sides you could and should now refer the matter to CEDR for their consideration. LHR-SEA seems particularly robust as a claim, in my view, ORD-LHR - we don't have enough information but CEDR should bring that up that data. If it's under 4 hours then it's £260 per passenger.