Just a couple of points .........
I've been following the original thread since around September last year, and this thread since it started. To my knowledge, prior to Juan's post, nobody in that time has identified the existence of, or the words of, the disclaimer regarding staff travel when you sign for it.
The existence of the disclaimer and the frequency with which it is continually being reinforced, clearly stating that there is no obligation on BA to either allow it in any instance or to continue to do so, leads me to believe that this alters all of the theories discussed and put forward, including any idea from BASSA or UNITE, that BA can in any manner be forced to give ST to anyone.
If I have an item and the sole ownership of it, tangible or otherwise, that some one else desires to have or share, I am the sole judge of what I shall do with my possession, regardless of any screams of 'give me' or 'I demand', and if I so wish I am fully at liberty to destroy that item. As indeed I am to run out of patience with any person I employ in my business, and say - you are fired - you have the legal right to sue me if you wish - I reserve my position regarding reasons.
I believe that BA may be very close to this response.