(1) A cause of action is not cognizable against a person who in good faith files a petition under this chapter alleging that an individual is a person requiring treatment, unless the petition is filed as the result of an act or omission amounting to gross negligence or willful and wanton misconduct.

  (2) A cause of action is not cognizable against a preadmission screening unit or its employees or contractors or a crisis stabilization unit or its employees or contractors, who in good faith makes a determination as to whether an individual is a person requiring treatment or not, unless the determination is the result of an act or omission amounting to gross negligence or willful and wanton misconduct.