So, compare this contemporary review, which makes it clear (including a quote from Zimmer himself!) that while Zimmer, Djawadi, and others contributed leitmotifs and notes, the majority of composition was Badelt's. Now consider Zimmer's website's description, which invariably paints himself as the main composer of nearly every track, even claiming the title of primary composer, and seems to erase the contributions of Badelt at every opportunity.

So, I take any claims of Zimmer's greatness with a giant salt lick. I originally read another source (which I now am unable to locate) that claimed the only thing Zimmer wrote for the DaVinci Code was the main theme motif, much like "He's a Pirate" for the first pirates movie. I now generally assume that anything excellent "composed" by Zimmer was some other collaborator's work, Zimmer offered a chord or two, then used his ill-gotten fame to bully the less-famous collaborators to accept the title of second fiddle while Zimmer mimes the Solo in the spotlight.