Terminology can be confusing, but... let's clarify what "DAO" is. That means double action only - double action on the first shot, double action on the last shot, and on every shot in between.
The 3913 is a "traditional double action" - TDA to some, or simple DA with a decocker. It is not DAO. Its hammer is bobbed, so it is not convenient to thumb-cock the hammer, but it is nonetheless a traditional DA auto which, after firing, will have the hammer in the cocked position until decocked via the decock lever(s). Assuming a TDA gun starts with a loaded chamber and hammer down, the first shot is double action and subsequent shots are single action.
One visual characteristic of DAO semi-autos is that they have no decock lever, since they can't be left with a cocked external hammer. So your tipoff that the 3913 is a traditional DA is that it has a decock lever (or levers, depending on model).
Great little gun... especially the LS. I want one!