D was charged with inciting his daughter to commit incest (an “act of gross indecency”) and he pleaded guilty. However, CA said that since “incitement” refers to trying to get another to commit a crime, and since the daughter was incapable of committing a crime against an act designed to protect her (as would have been the case here- Tyrell principal), D had committed no crime (he couldn’t be said to have incited V to commit a crime when V would not have been guilty of committing a crime). Therefore CA said that it was open to D to appeal the verdict (this was just a sentencing hearing)
The crime was that it was illegal for a woman to permit a man known to her to be a relative to have sexual relations with her. Another law prevented a girl under 16 from being guilty of the offence. Thus, since it was not a crime for a girl under 16 to commit incest, it could not be a crime for the father to incite her to do it.