The binding legal principles are: (1) Section 35(3) fair trial rights apply to "every accused person" being tried in the constitutional era, but do not extend to persons already convicted and sentenced under pre-constitutional law who merely require sentence substitution due to a change in constitutional law rendering their sentences unenforceable. (2) Section 12(1)(a) of the Constitution provides a twofold protection against deprivation of liberty: there must be just cause and the procedure must be fair. This applies even where section 35 rights do not. (3) In assessing fairness of a sentence substitution procedure under section 12, courts must consider the extraordinary context, including that: sentences were lawfully imposed, all relevant evidence was led at trial, the ultimate appellate court confirmed the sentences, and the only reason for substitution is that the sentence became unenforceable. (4) A legislative mechanism allowing written argument, potential oral argument before a judge, and judicial review of the executive decision satisfies the fairness requirement in such extraordinary circumstances. (5) There is no absolute separation of powers bar to judges performing administrative tasks or executives participating in sentencing, provided: for judges, the task is not incompatible with judicial office and maintains judicial independence; for executives, the essence of the judicial function (determination of sentence) remains with the judiciary. (6) The Constitutional Court has jurisdiction to issue supervisory orders, including mandamus, to ensure effective execution of its orders and vindication of constitutional rights.