Sim, existem exceções.
Em Ordem da Fênix , Harry é atacado por dementadores e usa um feitiço de Patrono para defender a si mesmo e a Dudley. Ele é expulso de Hogwarts e convocado para um julgamento, onde uma violação do Estatuto e do Decreto é listada entre as acusações:
Tanto Sirius quanto Hermione fazem alusões vagas ao fato de que o Estatuto permite que você faça mágica para proteger sua própria vida. Sirius diz isso diretamente:“Disciplinary hearing of the twelfth of August,” said Fudge in aringing voice, and Percy began taking notes at once, “into offences committed under the Decree for the Reasonable Restriction of Underage Sorcery and the International Statute of Secrecy by Harry James Potter, resident at number four, Privet Drive, Little Whinging, Surrey.
“Don’t worry,” Sirius said. Harry looked up and realized that Sirius had been watching him. “I’m sure they’ll clear you, there’s definitely something in the International Statute of Secrecy about being allowed to use magic to save your own life.”
e enquanto Hermione não cita a lei exata, o que ela diz tem o mesmo efeito:
“They haven’t even reported that you broke the International Statute of Secrecy. We thought they would, it would tie in so well with this image of you as some stupid show-off. We think they’re biding their time until you’re expelled, then they’re really going to go to town - I mean, if you’re expelled, obviously,” she went on hastily. “You really shouldn’t be, not if they abide by their own laws, there’s no case against you.”
No julgamento de Harry, como parte de sua defesa, Dumbledore faz referência a parte do Decreto que permite salvar sua própria vida (ênfase minha):
“We are here to examine Harry Potter’s offences under the Decree for the Reasonable Restriction of Underage Sorcery!”
“Of course we are,” said Dumbledore, “but the presence of Dementors in that alleyway is highly relevant. Clause Seven of the Decree states that magic may be used before Muggles in exceptional circumstances, and as those exceptional circumstances include situations which threaten the life of the wizard or witch him – or herself, or any witches, wizards or Muggles present at the time of the—”
“We are familiar with Clause Seven, thank you very much!” snarled Fudge.
“Of course you are,” said Dumbledore courteously. “Then we are in agreement that Harry’s use of the Patronus Charm in these circumstances falls precisely into the category of exceptional circumstances the clause describes?”
“If there were Dementors, which I doubt.”
É razoável supor que essa proteção se estende a assistentes maiores de idade, especialmente porque são mais capazes de se defender e / ou trouxas. Não há razão para não fazer isso e é uma adição sensata a qualquer lei.
A forma como Dumbledore formula sugere que as circunstâncias que ameaçam a vida não são apenas tais exceções na lei, mas eu não acho que isso esteja estabelecido no cânon, quais são essas exceções.