If the military member's home state is not California, then boxes 15-17 should be totally blank on their military W-2.
If you have numbers in 16 and/or 17 and nothing in box 15, and you use the EIN from box b instead, the tax filer may get audited by mail at some time in the future, by the CA FTB. Can't say an audit will definitely occur. But as bad as CA is hurting for tax money, it would not surprise me at all.
