Sounds like BB is suggesting there's reason to believe that Burbank will find that the agreement b/w the Executive Committee and the NFLPA on the salary cap reduction supersedes (or perhaps is incorporated into) the 2011 CBA such that no challenge under the CBA can be brought. That result would surprise (but not shock) me. And I don't really see a plausible basis to foreclose challenges to procedural irregularities in the cap reducation agreement (even assuming the agreement forecloses substantive challenges to the propriety of the reduction under the CBA).
It's not easy to believe that Burbank will just dismiss the grievance--that would effectively mean that the Executive Committee and NFLPA could agree to anything (make the Skins play a game with 10 players on the field at a time) and it would be unreviewable. We don't know how the cap reducation agreement was worded, which may be key; maybe the NFL's attorneys put in language intended to result in the reduction supplanting (or becoming incorporated into) the CBA, thus putting a large roadblock in the way of a challenge.
Assuming Burbank dismisses our grievance, I'd think our next move would be to appeal to the Appeals Panel (i.e., not yet go to court) to buy time. We could attempt to leverage a settlement as that process unfolds. And I disagree to a fair extent with tshile about whether filing suit means control is no longer in our hands and a judge might do anything; we could always agree to dismiss the suit, only seek certain discovery, etc., if things seemed to be getting out of hand. It would certainly deeply alienate the rest of the league, no small issue. But if an antitrust suit succeeded, the NFL's parity would likely fade, and the league as a whole might well be less profitable--but the Skins and Cowboys might well still win in such a scenario, turning into the Yankees and Red Sox of the NFL (getting a significantly larger slice of a somewhat smaller pie).
Another possible route would be to submit a contract to the league that would put us over the cap, then have the NFL reject it, then if we file a grievance challenging that decision, the burden of proof would shift from a heavy burden on us (as it was in this proceeding) to a heavy burden on the NFL. The problem with this approach, assuming the motion to dismiss is granted, is that the jurisidictional issue of whether we have any right to challenge the reduction is a threshold, legal issue that likely isn't affected by the burden of proof.