Dave's answer is what I would have said. LEGALLY its the 1 liter person person. But as Dave said it depends on how you answered the questions and what the customs officer feels ok with. Since you we honest he let it go. The duty on that alcohol would not have been that much and they are trying to stop the people trying to bring back enough for resale. It may have been border line on what that customs official was willing to let slide but the paperwork and time to collect the duty for such a small amount was probably not worth it.
When they do those types of things for me I tend to just smile and say "thank you sir, have a nice day" and quickly move along.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013