(a) A person who fails to survive the decedent by 120 hours is deemed to have predeceased the decedent for the purpose of intestate succession, and the heirs are determined accordingly. If it cannot be established by clear and convincing evidence that a person who would otherwise be an heir has survived the decedent by 120 hours, it is deemed that the person failed to survive for the required period. The requirement of this section that a person who survives the decedent must survive the decedent by 120 hours does not apply if the application of the 120-hour survival requirement would result in the escheat of property to the state.
(b) This section does not apply to the case where any of the persons upon whose time of death the disposition of property depends died before January 1, 1990, and such case continues to be governed by the law applicable before January 1, 1990.