However, I have also read that the opt out may fail if tested the correct way, so it is precedent time,
To an extent - and that's why it's an example of the lawyers licking their lips at a nice big fat fee. However, as I understand it, that would be a matter of finding against the
UK, not against BA, because it would be the UK in breach whilst BA were merely following English law as it currently stands.
Now, I'm no lawyer, so would welcome correction, but as far as I can recall, in these instances the requirement is on the state to change the law to comply, rather than the company to offer redress specifically.
That being the case, even if it did go to the ultimate end, I can't see how it would benefit those who have lost their staff travel right now. To use an example, the ECHR found against the last government over the question of DNA retention - when they gave their judgement it then took that government several months to come up with a response, during which time there was no right for people to have their profiles removed from the database, and even then the government came up with a response that caused campaigners to state that it wasn't good enough and was probably still in breach. That particular campaign has been made moot by the arrival of the new government determined to change the rules on it completely, but it's a good example of even a ECHR ruling not meaning that all is suddenly fine and dandy.