ADW can be extremely silly as a category, things like shoes and even just the body can be classed as a deadly weapon, the actual factor usually is how injured the victim was. You're exactly right. Given that the marines weren't injured, by definition it cannot be ADW.

There are things like knives and guns that are considered "deadly weapons per se" by some states, but those weren't present here, and that doesn't necessarily result in ADW if the victim isn't injured, just that there doesn't need to be evidence that the assailant is capable of causing serious injury.