It worked perfectly — the crackers missed the later checks. Anyone who torrented the game found that it crashed reliably as soon as you completed the first level. Game over.
Unfortunately, this did not generate the kind of PR he was hoping for. In fact, all this did was give the impression to everyone who pirated the game that it was a buggy piece of shit. Since there was no obvious reason for the odd behavior, they assumed it was the fault of the application. They stormed the gaming review forums and discussion boards, complaining about how the game was "shitty" and "unplayable". Nobody was keen to mention that they had pirated it, so there wasn't an obvious trend. At the time, the ratio of pirated video games to legal ones was about 10:1, so the bad feedback overpowered the good feedback by about 10:1. He was ruined.
Be careful about anti-piracy. You just might succeed.
Great article from the developers about this: