Separate trusts for spouses are rare in community-property states like California, so the daughter is especially clueless about what happens in a place that still calls itself a commonwealth.  If it turns out that  the house is owned by an irrevocable trust, does it even still qualify for the $250,000 exclusion?  Does that matter?  

Presumably the buyer wants title insurance, so the seller will have to comply with whatever is required for that.  The lawyer, or more likely the paralegals who do most of the work, are what would be known as scriveners, back in the days when commonwealths were common.