She said the cause of the problem was that the work was commissioned by "a part of the business that does not usually commission design work and there was an error in judgement and process".
Sims departed the state-owned company in May to head an airline in Canada.
Lamb said Airways appointed a new brand agency in June.
Staff at Airways were said to be ''gutted'' by revelations of the cost of the book. It is understood he was farewelled at three morning teas at Airways offices in Christchurch, Wellington and Auckland where sausage rolls and lamingtons were served.
Airways said the total cost for the farewell events was $3,317. Along with the $11,471 book, there was also a gift which cost $439.
Airways is a state-owned enterprise that provides air traffic control to New Zealand and the Pacific.