flyinspanner
I think you are under a couple of misapprehensions:
You are right that BA do not have to divulge sensitive data. But any data that they DO divulge must be accurate if it pertains to commercial performance. Also, there has been no verifiable misinformation from BA but it is hard to find a single piece of verifiable info from BASSA that is not grossly distorted or just a plain old lie.
I don't think it is fair to paint this a a challenge to impositions. The union had over a year to negotiate but wasted most of this time not talking to the company or not even talking to itself! Meanwhile all the other unions were coming to workable arrangements. Do you really think that taking a year to talk seriously is reasonable. By that measure, all any union would have to do is just refuse to talk ever and then nothing need change, ever!
I have personally met no FC who support the IA and I would estimate that I have had contact with around 150 since the IA was announced. If there are any, then its a tiny minority.