I have a similar issue. For whatever reason, Google has decided our CEO (Glen Kelman) is the 'author' of some of our site pages. There is no author markup on the page anywhere. In fact, our CEO's name isn't anywhere on the page. Yet, in SERPs, he is the 'author' of our Seattle market page (you can likely see it by searching for 'seattle real estate' and looking for Redfin in the results).
Glen is a prolific blogger who not only posts to the Redfin blog, but also guest blogs on high profile sites around the web so it stands to reason that Google is very 'familiar' with him as an author. Moreover, he lives in Seattle so maybe Google is thinking, "Glen is from Seattle...he's the CEO of Redfin...he's a prolific author...Glen + Seattle + Redfin + Author = Glen is the author of the Seattle market page on Redfin!" 
Any ideas on how to stop Google from making this mistake?