In Season 11 of It's Always Sunny In Philadelphia took the gang to court. We finally learned how and WHY Charlie is so good at Bird Law. Always Sunny is no where near a politically correct show, especially when it comes to practical law.
Yet a BAR certified Lawyer analyzed not only the entire legal proceeding, but even Charlie and his bird law!
In no real surprise, he gives the gang an F grade on legal accuracy. Probably best that they keep out of any actual courtrooms.