The expertise you'd want for drilling an emergency rescue tunnel would be a combination of skills related to drilling roughly pipe-sized vertical shafts [1] (mining/oil services, or maybe the companies themselves; I don't know what the exact breakdown of work packages end up being) and remote (specifically mountainous and jungle, in this case) infrastructure and logistics, which is military or again mining/oil services. Possibly a geologist or two on hand to assess the rock layers and identify hydrographic hazards as well as risks such as accidentally causing cave-ins. For the cave diving extraction, you'd want experienced cave divers, ideally ones with good first aid knowledge and cave rescue experience. For any further expertise, I wouldn't suggest anything without hearing the observations from the cave divers who have just explored the cave themselves.
There is no evidence presented that Musk, nor any of his companies, has any of this kind of useful expertise.
[1] Emphasis here on vertical shafts. There is a world of difference between a tunnel-boring machine that tends to remain within a single geological stratum and a vertical shaft that is constantly cutting through several strata of different kinds of rock (that require different cutting techniques).
> There is a world of difference between a tunnel-boring machine
Yeah it wasn't the machine he was offering but the expertise.
I get it, you've got it in for Musk. Fair enough, and I'm not out to hero worship him but lets be fair here - he did offer to help, and did so in good faith.
I added the footnote to emphasize why I thought The Boring Company was not relevant expertise, which you seem to have ignored or missed. Considering that Musk touted what SpaceX could do for the trapped people, not what The Boring Company could do, I also suspect that Musk recognizes the difference.
My contention isn't that Musk didn't make a good-faith offer to help, it's that Musk didn't have anything useful to offer. The end result is that would come across as something like this: https://xkcd.com/793/.