- Margaret immediately recognizing Ozzie, as well as her comment about Ozzie having "backed himself into a corner again"
- The very different yet compatible miniaturization technologies
- Scrimshaw's fairly extensive knowledge of the miniaturization process and its capabilities
Given that Ozzie doesn't seem to be very street smart, a possible backstory can be recreated:
- Ozzie came up with the concept and basic technology involved in miniaturization
- He ran through the financing he had (probably his own money) and unable to secure backers elsewhere, turned to Scrimshaw who - as he put it in the movie - was "only in it for the money." He didn't care what the ramifications of the tech were, but he saw the profit potential. Ozzie had backed himself into a corner financially and Scrimshaw was the only way out of it.
- With Scrimshaw's backing, Ozzie built and tested miniaturization tech, working with Margaret. She became aware of Ozzie's path in getting there, hence her offhand remark later when they ran into each other.
- Once he became aware of Scrimshaw's plans for the tech and his complete amorality, idealist Ozzie bolted with the work that had been done. Scrimshaw had half the process, miniaturization, and Ozzie took off with the research that had been done on re-enlargement. Scrimshaw knew it could be done and possibly had a line on the rough idea of how, but the details hadn't been developed yet. Ozzie had half the golden goose.
- Ozzie was able to persuade Vectorscope to fund and support his research by showing them the half that was complete. They saw the profit potential, too, and decided to get in on it.
- Scrimshaw becomes aware of Vectorscope's work (which wouldn't've been difficult) and bides his time until they seem close to a breakthrough on the re-enlargment process, at which point he attacks the company to get the research Ozzie skipped out on.