At the center of the bombshell New York Times story on the alleged bribery scheme that fueled the expansion of Wal-Mart Stores Inc. throughout Mexico is the account of Sergio Cicero Zapata. An in-house lawyer in Wal-Mart de Mexico’s real estate unit, he’s the one who told both Wal-Mart international general counsel Maritza Munich and the Times that the company doled out millions of dollars in payments to Mexican public officials.

Cicero’s very public whistleblowing—and what we know of him so far—defies pat categorization. He was a Mexican in-house lawyer who went to the U.S. media with a story that implicated him in the alleged wrongdoing at one of the world’s largest companies. We don’t know for sure if he ever told any government authorities on either side of the border about what happened. But his story shines a light on the gray areas of U.S. law when it comes to how whistleblower provisions apply to foreigners, particularly in an era of heightened enforcement of the Foreign Corrupt Practices Act.