I don’t think you want to separate what’s happening in SD county with the OC and LA markets. Overvalued is overvalued, regardless of location. San Diego is widely considered to be one of the canary towns in the nation because the specufever started here first and ended here first. That’s why all eyes have been on SD. The economists want to see out how those trends will play out in other town.
The fact that the OC hasn’t suffered much yet doesn’t mean the trend will simply pass them by. In fact, their declines may manifest themselves more quickly as their trend plays catch up.