If a US-based individual has worked for a Canadian co as a "partner" for years (but never signed an agreement), who retains rights for work completed?

Scenario: • Two individuals agree to start two startups together. • One individual resides in Canada. • The other individual resides in the United States. • The Canadian individual requests a partnership agreement from day 1, however the US based individual creates reasons to not have one yet. • The Canadian-based individual incorporates a company in Canada as the umbrella company for both startups, with no agreement with the US-based individual yet. So the Canadian corporation's shares are 100% assigned to the Canadian individual in the "meantime" until an agreement is reached. • Discussions lead to conclusions that the US-based individual will get 30% shares, when an agreement is signed. • The US-based individual was given an email for the Canadian based corporation, and began to work/associate work with both startups under the Canadian corporation. • After 3 years of pro-bono "partner" work as investment into the Canadian-based corporation, the US-based individual never signed an agreement yet. Questions: • Given that work was completed by the US-based individual ("partner") and he was operating with no agreement under the Canadian corporation's environments, emails, discussions - does the Canadian corporation retain rights to the work completed? • If the US-based individual ("partner") decides to take one of the startup's intellectual property, work (which was completed by both the Canadian-based individual and US-based individual) etc, and setup a US-based corporation with it, can he get sued? Or is he safe since he never signed an agreement with the Canadian-based corporation? • Do legal entities in the United States take lawsuits in performance / win payout shares (if the case is big enough)?