Probate Code § 5625

(a) Any person generally competent to be a witness may act as a witness to a revocable transfer on death deed.

(b) A revocable transfer on death deed is not invalid because it is signed by an interested witness.

(c) If a beneficiary of a revocable transfer on death deed is also a subscribing witness, there is a presumption that the witness procured the revocable transfer on death deed by duress, menace, fraud, or undue influence. This presumption is a presumption affecting the burden of proof. This presumption does not apply where the witness is named as beneficiary solely in a fiduciary capacity.