When University of California at Santa Barbara professor Nelson Lichtenstein came onto CNBC to discuss bribery allegations against Wal-Mart De Mexico (a subsidiary of Wal-Mart), he got more than he bargained for.

Kenneth Langone, an investor who helped found Home Depot, had joined Maria Bartiromo for the full hour of “Closing Bell” on Dec. 18. Langone, who is also the CEO of Geeknet and has a net worth of $1.6 billion, challenged Lichtenstein fiercely, demanding to hear facts from him. When he found out the news source Lichtenstein was citing as proof, Langone took a jab at The New York Times as well.

Lichtenstein argued that the accusations against Wal-Mart were just the “tip of the iceberg” of a “larger pattern for the company” of the company moving into an area of finding local ways of doing things and imposing “its own business model, regardless, on these countries and on the communities there.” (See CNBC video)