In a criminal proceeding the question is not alone whether substantial justice has been done, but whether justice has been done according to law. All proceedings in poenam are, it need scarcely be observed, strictissimi juris; nor should it be forgotten that the formalities of law, though here and there they may lead to the escape of an offender, are intended on the whole to insure the safe administration of justice and the protection of innocence, and must be observed. A party accused has the right to insist on them as matter of right, of which he cannot be deprived against his will; and the Judge must see that they are followed.

Martin v. Mackonochie (1878), L. R. 3 Q. B. 775.