This whole spat is really unfortunate. Musk's "pedo" comment is clearly unacceptable and is likely going to result in unnecessary and potentially costly distractions for him, Tesla, rest of his companies, and I believe indirectly us Tesla owners too. Issuing a sincere and unconditional apology is the least that Musk should do ASAP.
I'm also quite befuddled on Unsworth's initial comments that I think were, quite frankly, below the belt. Totally uncalled for IMO. If you want to say that you don't think the kid submarine would've worked, just say so. It was really unfortunate that he added a comment that I think amounted to a personal attack with the "stick it" reference. The question is why did Unsworth have such a visceral reaction when asked to comment on Musk?
My theory is that he wasn't happy with Musk's level of "involvement" in the whole rescue process (Musk's tweets throughout that whole rescue period and showing up in person in the cave) when he might've thought that he and everyone else at the location already had things under control. What's tragic here is that Musk himself didn't ask to be involved, but rather was asked on Twitter to consider ways he could help when the rescue team hadn't finalized their rescue plan yet. I believe that he's a genuine problem-solver who feels challenged when a tough problem like this comes up, and why he and his SpaceX team ultimately came up with the kid submarine solution based on feedback from one of the lead divers (Rick Stanton, who I think likely considered this as a back-up solution). Stanton and Unsworth were there and surely communicating, and if Unsworth didn't believe they needed a back-up solution or that he thought the submarine one wouldn't have worked, I wonder if he verbalized this and if it was communicated back to Musk. All of that aside, it seems to me that Musk and his SpaceX team really worked their asses off to make their idea a reality in the space of a few days out of their genuine desire to wanting to help in some way. And I think this is where and why Musk took such an umbrage when their solution was criticized later on. As to whether he needed to have showed up in person in the cave, probably not but it seems like he was planning travel to the region anyway (with the announced Tesla China agreement just the next day). I feel like this particular aspect shouldn't have been made such a big deal as it appears to be.
Lastly, Musk appears to have a rather thin skin, which is not a good combination when he speaks his mind so freely and does so in such a public forum as Twitter. One of those has got to give: either he's got to have way thicker skin, watches what he speaks more, or reduces his activities on Twitter.