7. a. Except as provided in subsection b. of this section any person knowingly violating the provisions of this act including the failure to report an act of child abuse having reasonable cause to believe that an act of child abuse has been committed, is a disorderly person.
b. Any person who knowingly fails to report an act of sexual abuse against a child and who has reasonable cause to believe that an act of sexual abuse has been committed is guilty of a crime of the fourth degree.