[p4wnc6]

> He finds Jeremy, they talk, they hit it off, and they decide to apply to YC together, and Kyle offers to split the existing company 50/50. But they don't put anything in writing...

One of the major questions is whether the YC application and any stated intent for a 50/50 split in it would be that writing.

[henrikschroder]

Kyle fired(?) Jeremy after a month, was that a valid withdrawal of the verbal promise to give Jeremy 50% of the shares? Jeremy left, and did not in any way indicate that he still thought he had 50% of the company, is that an implicit acceptance of losing his promised shares?

[p4wnc6]

That all sounds complicated and open to debate. Was Jeremy an employee? Did Kyle have any standing to fire him? What were the circumstances under which Jeremy left? Did Kyle use any primary IP contributions from Jeremy, like architectural designs?

Also, if there is sufficient evidence to declare that the 50/50 partnership existed, then Jeremy did not have to do anything to explicitly declare or let Kyle know that he (Jeremy) understood himself to still possess a 50% stake. There would be no such thing as an "implicit acceptance" of losing equity.

Basically the points you raise are not at all obviously addressable, and there are many ways they could play out that actually do support a significant award to Jeremy, regardless of whether that is a popular outcome.