On the back of the card with the "how to help a choking victim" instructions, Harry reads "hit the person on the back to dislodge the obstruction". It is generally advised not to hit a chocking person on the back as it could make the obstruction fall further down the trachea.
The priest tells Harry "judge not, lest ye be judged", an out-of context quote from the Gospel of Matthew. However, there is no Biblical prohibition against duly appointed judges presiding over established courts of law. This is particularly ironic given that the Roman Catholic Church operates the largest court system in the world.
Harry ends the court session by stating "Court dismissed". The correct term is "court [stands] adjourned", or for a temporary break, "court in recess".
When the priest is admonishing the court, he declares that "no sin has been committed here". However, it is the purview of the civil courts to adjudicate crimes, not sin. Many crimes are not sins (e.g. jaywalking) and many sins are not crimes (e.g. adultery), and a priest should know this.