Well BA won't like this, but there may be scope to take this further against BA, there have been successful cases in this space. But a lot depends on exact timings, so I would get the family to note down what they recall about this, plus whether other people were also affected. If they genuinely turned up in good time then I would hope they would get something back from this on the basis that they fulfilled their side of the contract. As ever a lot will depend on the details.