There is nothing childproof; the case is based on the water present in the house on the floor not on the access to the pool.
Nowhere in the article was it stated that the pool and its surroundings were in violation of the applicable standards.
The father wasn’t present one assumes, his presence now would make a good story to see how the suit might affect all parties.
So if the locality has weak standards, you aren't responsible for your child?
There is nothing childproof
A deadbolt lock in the door, with the key not present isn't childproof? A gate with a latch at least 48 inches from the ground won't keep out a one year old? My, your children must have been really advanced at that age. An old fashioned hook and eye latch on the door would be effective for most one year olds. (There's a reason most of the pool drownings are in the 3 - 5 year age group.)