What is the test for establishing a corpus delicti of oral sex?

"Defendant, however, contends that the prosecution failed to establish the corpus delicti of oral copulation because no semen was found in the victim's mouth. In other words, he argues that the lack of evidence of the specific loss or harm to this victim is fatal to the establishment of the corpus delicti. The law's requirements, however, are not so strict." (People v. Jones, supra, 17 Cal.4th at p. 302.) "[W]e have never interpreted the corpus delicti rule so strictly that independent evidence of every physical act constituting an element of an offense is necessary. Instead, there need only be independent evidence establishing a slight or prima facie showing of some injury, loss or harm, and that a criminal agency was involved." (Id. at p. 303.)