Possible outcome?
Here's my prediction....
The ballot results are announced, BA challenge the probable resulting mandate for strike action as being illegal for any number of reasons (previously discussed), warning BASSA that they consider that any strike action will be unprotected. It probably won't go to court, as BA are fed up with going over the same old thing, it's time to finish this dispute. BASSA either hesitate and drag things out, or go for it. The first person who doesn't turn up for a rostered duty is sacked, and then the second, and so on. As the industrial action is probably unprotected, the dismissals are probably not unfair in the eyes of the law. In any case it's goodbye BASSA in it's current form.
Be very careful if the above turns out to be true but BASSA tell you you'll be okay, because they've been wrong before and it's your job at stake. BA have nothing to lose using the above strategy, and everything to gain.