As a global investor, the Mitsui Group wasn't just capable of forking 5 billion easily—they could say with no uncertainty that they could profit steadily with it.
If Yoshitaka did as Charlie asked, that meant he was giving up on 780 million US dollars and basically giving him the money for free… and that was only if he did everything demanded flawlessly, or it would be 5.78 billion dollars in total loss.
Yoshitaka would bawl if he could—as a businessman, profit was the only thing he cared about,