The 16-page ruling from Judge David Doty that reinstates Vikings running back Adrian Peterson turns on one fairly simple conclusion: The NFL cannot apply its new personal conduct policy retroactively.

“There is no dispute that the Commissioner imposed Peterson’s discipline under the New Policy,” Judge Doty wrote. “It is also undisputed that in the [Ray] Rice arbitration, the hearing officer unequivocally recognized that the New Policy cannot be applied retroactively, notwithstanding the Commissioner’s broad discretion in meting out punishment under the CBA. . . . Consistent with that recognition, the Commissioner has acknowledged that he did not have the power to retroactively apply the New Policy: ‘The policy change was forward looking because the League is “required to provide proper notice.”‘ . . . Yet, just two weeks later, the Commissioner retroactively applied the New Policy to Peterson.”

In other words, Judge Doty concluded that the NFL was making it up as went along.

Some will surely criticize Doty for “rewarding” a man who spanking his four-year-old son until the boy’s legs bled. But this isn’t about criminal justice; this is about respecting the terms of the labor deal that the NFL and the NFLPA have negotiated. It may be easy for the NFL to impose stringent consequences based on the underlying facts, but that doesn’t justify violating a player’s rights.

Meanwhile, the NFL has appeal rights in this case. It’ll be interesting to see whether the NFL tries to get Judge Doty’s ruling overturned, or whether the NFL will attempt to erect other roadblocks to Peterson’s return to football.