Here's how they should have ended it.
Ian peeks through the rubble and sees his dad embrace Barley, then the light of the setting sun gets in his eyes and he slides down. He manages to get out himself, all sad and dejected because his dad is gone. He climbs out and sees Barley and their dad standing there arm in arm! The combination of the botching of the first spell and the success of the second has made the restoration of the dad permanent.
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