I never trusted other people with my small kids and water. Even though the lifeguard is trained and has the best intentions, no one will distinguish my child from the others the way I will. The sun, the reflections, the little identical looking heads above the water...sometimes things go unnoticed.
According to the article, the mom told the people in charge that she didn't want her son in the pool. If they can prove that, I don't see how they can lose this lawsuit.
I'm very sorry for this family's loss.