A Young Man by the Name of Mr

A young man by the name of Mr. Hicks works at an accounting firm which has a written ethics code of conduct. The code specifically outlines the duties and obligations that every employee must follow without question. One of rules states that every accountant should not lie under any circumstances.
Last week Mr. Hicks sent out a finalized tax return to the Wrong client. The Wrong client called Hicks and informed him that he was sending the tax return back to him overnight. Meanwhile the Right client called Hicks and wanted to know where the tax return was. Hicks told the Right client that he sent it to the wrong address and he will send out the return the next day. The Right client was irritated and called the partner of the firm.
The partner scolded Hicks and wanted to know why he told the client he sent the return to the wrong address. The partner said he should have told the client that the return was in the 2^nd partner review or some other excuse to cover up the mistake. Hicks explained that the ethics code of conduct specifically states that he should not lie under any circumstances and he was just following his ethical duty. The partner grinned and told Hicks that the next time this happens he should consult with the partner first.
Using the ethical decision making model and ethical theories, justify the positions of the partner, Hicks or an alternative solution.