I also think a No Swimming sign means no wading. To me, wading is a form of swimming. You don't have to be doing the backstroke in the middle of the Seven Seas Lagoon to be considered swimming, IMO.
Has it been determined though if the child was actually wading or just stepped into the edge of the water on the beach when this happened? As it's been alluded to in other posts, if it was the latter, I'm sure thousands of other guests have done the same thing over the years. Not saying that is right, I wouldn't personally go near that lagoon's edge, particularly at night, but can see how the parent would think it shouldn't present much danger, especially since this hasn't happened before. Even if I had done something similar with my child, I would place myself on the outside closest to the water as precaution (similar to what we've done on rides, keeping them on the safer sides of the vehicles if there is one).
Has it been determined though if the child was actually wading or just stepped into the edge of the water on the beach when this happened? As it's been alluded to in other posts, if it was the latter, I'm sure thousands of other guests have done the same thing over the years. Not saying that is right, I wouldn't personally go near that lagoon's edge, particularly at night, but can see how the parent would think it shouldn't present much danger, especially since this hasn't happened before. Even if I had done something similar with my child, I would place myself on the outside closest to the water as precaution (similar to what we've done on rides, keeping them on the safer sides of the vehicles if there is one).