Amy, here are a few lawsuits and/or investigations from my 1970s file on ethics:
Sackler wing probs, Met. Art News,Sept 1978, Nov. 1978
Brooklyn museum. Art News April 1978
Rothko foundation, Art news October 1977
Maryhill Museum, Art News March 1977
Museum Trustees and the law, Art News Nov. 1975
Old references but worthy...
Michael Bogle