Yes---he will owe CA tax. He worked and earned income---even though he worked in another state he has to pay tax to the state he lives in. And as a student being claimed as your dependent---he "lives" in CA. He paid no state tax in WA since there is no state tax in WA. But he will have to pay CA.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
