I agree with the Happy Guy.  Amending F.941's for the respective quarters would be the way to go since these were clearly payments that had already been made but were just misclassified.  Your client can't avoid penalties simply by zeroing out those "distributions" and reporting a make-believe bonus with net zero payment at year-end.

If no payments were made at all during the year and your client is declaring and paying an actual bonus to true-up what should be reasonable compensation, that would be a different story.