I'm a little unclear on why this play wasn't reviewable. All turnovers are automatically reviewed. Detroit had possession, fumbled, the ball ends up going out the back of the end zone, it's ruled a touchback and Seattle ball. It's not the traditional change of possession via INT or fumble recovery, but it's still a turnover, so there should be a review of the play.
If there was a review, the batting of the ball should be considered. I believe it was 3 years ago that Gronkowski caught a short pass for a TD. The play was reviewed and it was determined that Gronkowski stepped out of bounds while trying to get open and then caught the pass. Instead of getting the TD, the Patriots ended up being penalized for illegal touching. Tonight isn't the exact same situation, but if the play was reviewed, the officials should have seen the illegal batting by Seattle, called the penalty and proceeded from there.