Right up to the point where you need to cure someone in the middle of the court of justice that is heavily antimagic to prevent corruption of justice. You can't even teleport the patient out.
More targeted anti-magic would be wanted. Perhaps broad-brush -- no fire magic, no damaging spells, no mind control spells -- though the desideratum, of course, would be high precision. You would want most mind control and most attacking magic out of the court of justice, but a spell to compel truthfulness and -- perhaps steel golems that will righteously protect the court from mundane violence.
The next question after that would be how easily wizards can devise spells in the world.