I think the more likely scenario is who wouldn't you sue?

Even the camera manufacturer wouldn't be immune from defending themselves.

Welcome to America.

You wouldn't sue yourself as the parent/guardian of the child - you look around for someone, anyone to blame.

When I took a 5yo to a pool which had multiple lifeguards I put her in a lifejacket and stayed within arm's reach of her. Playing in a pool is great fun but it is very high stakes. No way I am going to leave a child in such a dangerous situation and hope it works out. Making sure your child survives a trip to a pool is your responsibility.

> as a backup

It'd be a tool that can warn the lifeguards in the event that they didn't notice the drowning, not the only thing that monitors the pool.

I suppose you sue the swimming pool for not taking proper measures. They can sue the device manufacturer, but this is not of your concern.