Can a witness be evasive in giving evidence at trial?

"[a]lthough [the witness] consistently denied at trial being able to remember anything that defendant had told her, what she had told the police, or her prior testimony, the record provides a reasonable basis to conclude she was being evasive. [Citation.] She had been a friend of defendant's and admitted she was reluctant to testify and had failed to appear at a previous hearing. She claimed that even reading her prior testimony in full and listening to a tape recording of her police interview did not refresh her recollection." (People v. Ledesma, supra, 39 Cal.4th at p. 712.)