definitely not ethical and probably illegal because the girl was in a private area and did not consent.
i did some quick research and couldn't find california code which covers this, but then my research skills suck.
there are some other states that prohibit similar acts:
|13-3019. Surreptitious photographing, videotaping, filming or digitally recording or viewing; exemptions; classification; definitions|
A. It is unlawful for any person to knowingly photograph, videotape, film, digitally record or by any other means secretly view, with or without a device, another person without that person’s consent under either of the following circumstances:
1. In a restroom, bathroom, locker room, bedroom or other location where the person has a reasonable expectation of privacy and the person is urinating, defecating, dressing, undressing, nude or involved in sexual intercourse or sexual contact.
2. In a manner that directly or indirectly captures or allows the viewing of the person’s genitalia, buttock or female breast, whether clothed or unclothed, that is not otherwise visible to the public.
B. It is unlawful to disclose, display, distribute or publish a photograph, videotape, film or digital recording made in violation of subsection A of this section without the consent or knowledge of the person depicted.
|18-7-801. Criminal invasion of privacy.|
(1) A person who knowingly takes a photograph of another person’s intimate parts, as defined in section 18-3-401(2), without that person’s consent, in a situation where the person photographed has a reasonable expectation of privacy, commits criminal invasion of privacy.
(2) Criminal invasion of privacy is a class 2 misdemeanor.
(3) For the purposes of this section, “photograph” includes a photograph, motion picture, videotape, print, negative, slide, or other mechanically, electronically, digitally, or chemically reproduced visual material.
|CHAPTER 952 – PENAL CODE: OFFENSESSec. – 53a-189a. Voyeurism: Class D felony.|
(a) A person is guilty of voyeurism when, (1) with malice, such person knowingly photographs, films, videotapes or otherwise records the image of another person (A) without the knowledge and consent of such other person, (B) while such other person is not in plain view, and (C) under circumstances where such other person has a reasonable expectation of privacy, or (2) with intent to arouse or satisfy the sexual desire of such person or any other person, such person knowingly photographs, films, videotapes or otherwise records the image of another person (A) without the knowledge and consent of such other person, (B) while such other person is not in plain view, and (C) under circumstances where such other person has a reasonable expectation of privacy.
(b) Voyeurism is a class D felony.
CHAPTER 952 – PENAL CODE: OFFENSESSec. – Sec. 53a-189b. Disseminating voyeuristic material: Class D felony.
(a) A person is guilty of disseminating voyeuristic material when such person disseminates a photograph, film, videotape or other recorded image of another person without the consent of such other person and knowing that such photograph, film, videotape or image was taken, made or recorded in violation of section 53a-189a.
(b) Disseminating voyeuristic material is a class D felony.
i'd be really surprised if california had no prohibition like these.
to answer your question though, she may be able to get the police involved. even if they can they may not bother. even if they do get involved a prosecutor might not want to do anything (investigate charge etc) finally the girl could probably sue him civilly. there are a lot of ifs. short answer, you're friend shouldn't sweat it too much.