I wouldn't rely on a 1992 Tax Court memorandum opinion -- those are not precedent, although they can be cited to illustrate, among other things, that the law is so settled that it doesn't need to be reviewed by more than one judge.  In the Calhoun case, the wife was claiming that none of the unemployment should be taxed to her; the IRS, while having assessed the tax-protester husband for all of it, maintained that she really should at least be assigned half of it.  

The best sources for California community-property laws are California courts, but apparently Spidell couldn't come up with a state case.  Not many of the formerly unemployed can afford a trip to appellate courts.  But really, why is the outcome in doubt?  It's like asking for a Supreme Court decision that the San Andreas fault is going to cause some damage eventually.