It's something that has been argued. At one point the Walther webpage said it was, but at that point it said there were Military model QA's avaliable when there weren't. Lots of Walther marketing stuff has inaccuracies. You should see the slicks and catalog from the SHOT Show. (I've seen a pic from a HK ad where they loaded the magazine backwards- Oops!)
Here are the two sides-
When you rack the slide, the striker is partially cocked like a Glock. Some consider this modified DAO because part of the trigger pull gets the gun to full cock and then allows the striker to move forward.
Others consider it modified SA because the striker has to start partially cocked. Think of a 1911 or a Luger. You rack the slide and it is ready to go with a pull of the trigger. Same with the QA. If you don't rack the slide (or Toggle with the Luger) to cock it, the trigger does nothing. -For what it's worth, when I've shot IDPA matches they treated it as a SA semi-auto because that is how it behaves.
Most of the companies that have this type of system come up with a proprietary name. Glock calls it Glock Safe Action. Walther calls it Quick Action.
You can call it DAO, but it really doesn't do the action justice in terms of meaningful description. Typically you can pick up a DAO pistol, pull the trigger and fire. As I mentioned above, with a QA, you cannot set the weapon off with a trigger pull if it has been decocked. -With DAO model of the P99 you can.
Since it is not classic DAO nor classic SA, I don't think the terms are of much help.