Even if that's the case, it wouldn't be a legal issue really. Legality has to do with laws, not union policies. I don't see why one MEC couldn't take action against another MEC which is trying to change an agreement without an agreement of terms. Union might not like it, I suppose they might have the power to threaten to drop that MEC from ALPA, though they wouldn't ($$$).

But I could be mistaken, which is why I asked, in case I was missing something.