It's quite simple. Doctor soon created a buying frenzy that allowed the company to dilute enough shares to pay off YAG. Read the YAG loan agreement. If paid in full by the maturity date, YAG must return all of it's shares and is only entitled to 14% interest.
smooth; If you still have an assumption in there that might not be real.
The question should be: "so why would this put 3 mil into a stock." You don't think he has investment manager, maybe like the guy who signed the Form 4?
General answer is because they could make a return on investment.