Re, the potential of a libel suit, you do realize that Musk also has an obvious countersuit? Given that Unsworth went on international TV and made the false claim that Musk had been ordered off the dive site, among other things?
1. I don't know whether Mr Musk was ordered off the site or not but would tend to think it not unlikely.
2. Even if the statement were to be proven false, it barely amounts to a libel and will stacks up very low against a false accusation that the opponent is a "child rapist", which is a libel per se, imputing a felony, for which no monetary damage must be shown in order to prevail.