That sounds like a lot more work that what I did - which is just remove and re-add your account. Even with several hundred contacts, it only takes me a few minutes to re-sync everything over wifi. If you wanted to find the cause, I'd suggest rebooting to recovery, doing a full pull of /data, rebooting to system, remove and re-add your google account...then do another pull of /data from recovery after sync, and see what's different with beyond compare. There's a chance you could find the root source of the corruption. I'd do it myself, but obviously, I've already fixed the issue. If I could replicate it, I'd do just what I described.
Just wanted to throw that out there for anybody else who finds this issue and wants to help with a proper fix.