The vagueness alone is enough to realize it's aimless. I doubt I worked with lawyers at this particular level before, but their letters tended to be bullet proof in their detail and specificity. I would automatically question this one because it doesn't really say very much, yet takes 2 pages to attempt saying something.
It's bizarre that Spiro wouldn't already understand this, but even weirder that it appears he didn't even research the topic or have an associate/junior partner with more applicable tech knowledge give it the once over. Possibly, Spiro and Musk were provided that feedback and purposely ignored it due to their outsized egos.
What's most obnoxious though is that Musk fired the employees in question while avoiding paying their agreed severance, and then has the gall to invoke the specter of non-compete agreements. I would hope that Spiro, or his firm, would at least be aware that non-competes are unenforceable in California and many other states.
All of this shit is nutty as hell.
When I first read it, I thought some of it sounded really amateur. I've read lots of lawyerese (I used to provide expert testimony in certain types of technical cases), and this did not come across like it was written by a legal expert of any level.
Now reading this analysis, there are a lot more bells going off. I personally would disregard it - and if forced to respond, I would require a rewritten letter with an appropriate level of authority in its wording.