In a desperate scenario in which it was considered highly likely that all those kids would be unable to be rescued alive from the cave by any means at all, Musk said something to the effect of we have engineering and production resources at Tesla, we'll try and come up with a capsule in case it may be useful, and quickly built and delivered a device after close consultation with members of the rescue team on the ground, and also supplied various other forms of equipment and expertise.

Luckily the kids were rescued and the capsule wasn't needed.

That diver said Musk should 'stick his submarine where it hurts' - for no good reason.

As I said, Musk's reaction was inappropriate and he's paid a big price for it, but it was hardly without provocation.