The rule of law in a specific geographic area in a specific period of time isn't nearly as important as the meaning conveyed which is misleading.

Rather than missing the forest for the trees, why might he push for the title of founder? Why might some discredit his efforts and tactics in assuming the founder of title in specific contexts?

He did not play a meaningful role in the beginning of the company and is not responsible for its success. Money was responsible, the two founders' expertise was responsible, that specific person is not special enough for their contribution to matter much. Anyone can supply capital especially during the inflated economic conditions (of which we are suffering the consequences of now) and during the time where EV and technology at large was developed enough to allow such developments to take place.

This is the entire argument Musk made in court, and honestly I don't think I care. Tarpenning and Eberhard are both engineers with actual inventions and software attributed to their direct design long before the idea of Tesla; Eberhard wrote the company's mission statement and guiding principles, and the two did the market research to discover that an electric vehicle could be a high-end consumer product. At its core, before the battery technology and stators were invented (neither of which Musk contributed to), that's what Tesla was.

While it's true that Musk led development on the Roadster, I think we've seen very publicly over the past year what his "development leadership" looks like and I'm not entirely convinced it's a value-add. (Even before his disastrous year with Twitter, his checkered past leading Paypal—and being forced out for his poor leadership—would give a similar impression.) He didn't come up with the battery tech or the stators. He didn't contribute to a single patent in the early days of Tesla. In fact, that first design of the Roadster probably owed more to Lotus Motors than to Musk himself.

It appears that he did with the Roadster, and the early years at Tesla, what he always does when leading product development: jump into an existing idea, make wild assertions and insistences, let the actual engineers figure out how to do it, and then justify a reason to exclude stuff when it turns out to be unfeasible. He did this demonstrably with SpaceX, Hyperloop, Boring Company, PayPal/Zip2, and now Twitter, and he's done it demonstrably at Tesla with the Cybertruck, so I don't know why it would be a surprise that he did it twenty years ago at Tesla too. He doesn't invent things or lead teams, he just makes noise and bluster.

Which just leaves the money. And would you credit a really loud bank with "founding" a company?

I wouldn't.