We did have storms and lightning in our area (Ocoee/Winter Garden) last night so it is possible that the pool was closed due to weather. During that time when the pools are closed the fences are up and the area cleared. Normally the lifeguards are in the general area in case the weather clears and they re-open the pool but they are normally under cover and cannot see all of the pool area.
I will say I have seen many times kids and parents not obeying the signs and trying to go into the pools. We witnessed over July 4th two kids going around the fence at the main pool at the GF. Both made it in the pool before a lifeguard could get to them and tell them to get out.
I mean I've got video of people in the AS Sports pool during hurricane Charlie ... And WL during Frances.
Point being, guests seem fine going in the pool during a storm.
As for this instance? Awful for the family. Just takes an instant with your back turned....