The first argument is somewhat difficult to comprehend.  It seems that the union parties are using the legal arguments of the school district parties at the trial court both to show that there is a case and controversy and to make some sort of estoppel claim. Given that some of the e-mails still have not been disclosed, there does not appear to be a justiciability problem.  As to any estoppel claim, there is no indication that Zarko, the party actually seeking the documents, ever agreed that the disputed documents should not be disclosed.  Assuming that the district had made any important admissions at the trial court, none of them would be binding on Zarko.  Further, this case is likely to guide future actions between other public school districts and their teachers, most of who belong to teachers' unions. It should be decided on the merits, not a technicality.