The ending to the Hell In A Cell match between Seth Rollins and Bray Wyatt was met with negative backlash as the fans hated it.
According to the Wrestling Observer Newsletter, Vince McMahon was well aware Wyatt would not get the title and he was not going to beat Rollins this early.
The original idea for the finish apparently had nothing to do with a sledgehammer. Rather, it was to toss Bray Wyatt off of the Hell In A Cell structure.
The original idea for the finish was that Wyatt would take a gimmicked bump off the top of the cage and be unable to continue and the match would be stopped. Then, after it was stopped, he would pop up like Undertaker and take Rollins out with the mandible claw.
It is unknown why WWE went with the referee calling off the match.