Legal Question in Real Estate Law in California

The owner of the tree.

Generally, a damage claim might be made under one or more of these three theories of liability: trespass, private nuisance, and/or negligence. A trespass may be difficult to establish, because an element of trespass is the defendant's "intent" to trespass must be proven. When the case involves limbs overhanging the property line, the necessary element of intent can be established by the obvious presence of the limbs, but with a blow-over in a storm (or the like), the "intent" element is harder to establish...it's really an accident, or Act of God. Similar issues will arise in trying to prove the elements of a case of private nuisance. The damaged neighbor is perhaps most likely to prevail on a negligence theory. Even then, the neighbor would have to show that the tree owner neglected some responsibility toward him, such as failure to have the tree trimmed when obviously necessary, failure to remove it when dying or dead, etc.