As someone who has worked in early stage startups for 9 years now, I'd be hard pressed to believe that anyone who worked at a company for one month at its beginning was 'integral to the development of the company'. That's just not how startups work. The value isn't in the initial idea, or the detailed initial plan. It's in the hard work, the long nights writing code, the prototyping and testing, and prototyping and testing again, the recruiting, the sales, the fundraising, the deal-making. So no, I don't believe that anyone who has worked for 1 month at any company at any stage deserves 50% of that company. That is fundamentally unfair.

Fundamentally unfair happens all the time, especially when the law is at play. But unfair doesn't mean immoral, illegal, or even "mean".

Further I would dispute the notion that the value is in the hard work, long nights, etc. Value definitely does lie there and that's definitely measurable. But there's TONS of value in outlining the correct approach, dividing the problem correctly, etc. That's called architecture and I've worked on projects with none of it and it's a disaster.

For the starkest example of how this plays out, I would invite you to watch the NOVA special "The Great Robot Race" which outlines how all the competitors worked on getting "the best X hardware" where X was the piece that they thought was the most crucial to success including now giants like CMU. In the end it was folks from Stanford who recognized that the exact car, exact LIDAR, etc weren't the crucial missing link, but rather that the software was the problem. And they won based primarily on that insight and then successfully executing.

I have a counter-example. I worked at a small SaaS company where I built the foundation web service and performed query optimization that took from them a highly-inadequate non-scalable product to something that handled scale gracefully. A substantial amount of this work was done in my first month there - in my opinion, my domain knowledge ensured that what I did for them in this month would have taken them a lot more hardware and many months to even get close.

You seem to be very dismissive of turning-point ideas and crucial features that make or break companies. Archimedes' principle, the foundation of modern naval history, was a Eureka moment thought up in a bathtub. Should we ignore this contribution because it took moments to come upon this insight?

I am not taking sides here and wish to let the courts work through this complaint without casting aspersions on either side.