Sure, you can prove it is complex by measuring cyclomatic complexity. But, the harder part is to prove that complexity matters. (I don't think it does myself)

Sure, you can prove it is complex by measuring cyclomatic complexity. But, the harder part is to prove that complexity matters. (I don't think it does myself). Have you considered that maybe it doesn't matter? Is his code well tested, easily maintainable, ships with few bugs, and is produced on time? If so, who cares about complexity?