Not harsh at all. No question, you have to pay attention at all times and they are never left alone in the water. When they are, it's because no one saw them go in until it's too late. 

I think the issue is that kids with ASD are especially vulnerable and the normal precautions (locking doors, windows etc..) are not really effective. They can easily unlock doors and leave the house at any time especially at night since kids on the spectrum wake up at all hours of the night and are fully alert when they do. They have a tendency to bolt or wander for hours without any sense of danger or awareness just as an elderly person with dementia might do. As the author stated, young kids with ASD are utterly fascinated by water and will jump in without a thought.  Explaining the danger does not work since most have no real concept of what danger is. For some, you cannot convince them not to do this. The only way to save their lives is to teach them swimming basics .  

One kid in 68 has autism.