I agree, but for different reasons.

I think the author (or his friend at least) entered in the event to test his Speculative Stock Warrant. (It is a ways to get a small kick-back if startup goes big 10 years later) So he already entered in the event to only get an shadow option of a potential good company.

He complained that Billy did not valued enough their weekend hacking and put an outside parter in the company. But he already only had 0.4%. If I was Billy I wouldn't think of someone who had this kind of deal with me as a cofounder.