If your 2014 tax return already included an explanation statement for the return of contribution, there is no need to amend your 2014 tax return. If no explanation was included, the only purpose to amending would be to provide that explanation. Since the taxable amount is zero, you could instead just put an explanation statement in your personal tax records to use in case the IRS at any time in the future questions the return of contribution and respond with the explanation at that time.
