Tournament rule 702.8.b.1

If possible, perform a simple rewind to before the card or ability was put on the chain. If a simple rewind is not possible, instruct the players to continue playing.

• 702.8.b.1.a If overpaying a cost was advantageous to the erroring player, this penalty is a [Warning] instead.
• 702.8.b.1.b If overpaying a cost caused a result that would not otherwise have happened, it is a General Error. See 702.15 for…

Official Tournament Rules