Legal Question in Real Estate Law in California

Only the half interest of the deceased joint tenant is reassessed. If the domestic partners had been registered, I believe there would have been no reassessment at all. However, without the benefit of registration, there is a reassessment UNLESS the joint tenants fall into a category known as "Original Transferors" -- a somewhat complex and to me rather silly circumstance in which, for example, each joint tenant had previously been a tenant in common in the property and had created the joint tenancy by transferring the property to themselves as joint tenants. Absent this shenanigan, the half interest of the deceased joint tenant will be reassessed. I would suggest contacting someone in the assessor's office to see if you can get a clearer explanation of the rules, specifically the concept of an "Original Transferor," and to see whether the concept might possibly apply to this (former) joint tenancy.