What is the burden of proving the voluntariness of a witness in a civil case?

"The burden of proof which must be sustained by the prosecution on questions of voluntariness is proof beyond a reasonable doubt. [Citation.]" ⁶ (People v. Hogan (1982) 31 Cal.3d 815, 835, 183 Cal.Rptr. 817, 647 P.2d 93.) As the reviewing court, we "... must examine the uncontradicted facts surrounding the making of the statements to determine independently whether the prosecution met its burden and proved that the statements were voluntarily given without previous inducement, intimidation or threat. [Citations.] With respect to the conflicting testimony, the court must 'accept that version of events which is most favorable to the People, to the extent that it is supported by the record.' [Citation.]" (Ibid.) The totality of circumstances must be considered in determining voluntariness. ( Id. at p. 841, 183 Cal.Rptr. 817, 647 P.2d 93.)