There is not enough detail here to answer. What does the software show when you enter the info for your client? What does the FTB tell you applies, once you read the reference that applies to your client? Why doesn't your client roll that 401k to an IRA? 

You made a nice simple statement, that if true would not have the 401k be taxed by CA. Often there is more to the story, so I would start my research at https://www.ftb.ca.gov/file/personal/residency-status/part-year-and-nonresident.html and see if all the facts and circumstances will be met to qualify for no CA tax on the 401K. 

There are too many "I" statements here. You might be lost on the internet.

Thank you, everyone for your help.

Thank you for providing me the website that answered all my questions.