If your client was a VA resident who commuted to KY for work, the reciprocal agreement stipulates that only VA has the right to tax the compensation.  You can't voluntarily pay tax to KY and expect a credit from VA.  A K-4 should have been filed with the employer to exempt the compensation from KY withholding.  If any KY tax was withheld, a return may need to be submitted to claim a refund.