I think the rescue sub idea is worth evaluating by studying the channel it would have to navigate to rescue the boys. It would have to be large enough at all points - larger is better, and it would need paths that this ~~9 foot?? long tube can go all the way through without the walls/floor/ceiling getting in the way. This is a rigid tube!! It is possible the locals knew very well there was no clear path.
That does not make him an engineering and/or business genius with carte blanche to behave as an entitled thin skinned idiot online. He's reached critical hype mass, there's enough people that think ha can make no mistakes and that everything he says must be true and smart.