Most associations have "appeal rights," whereby the accused party has the right to due process by having the right to have a hearing held before an arbitrator. I think that exists with the NFL.
The Yorks are wussies, so they won't challenge anything. But maybe fans can file a suit, claiming to be a "third party beneficiary" of these rights. Our argument is that Goodell is disparaging the good name of the 49ers, and that adversely effects the status all of us fans have relative to fans of other teams. Get a few fans to file a lawsuit in San Francisco against the NFL, asking for declaratory relief whether fans have the right to demand a formal hearing on the issue before the NFL. Don't need to hire any lawyers; we have plenty of SF fan lawyers or law students who could help move the case forward.
The League could not ignore the suit. They would have to have their lawyers defend it. They would not like any more negative publicity right now.