It is not unusual to find in Bills of Rights provisions to the effect that rights shall only be subject to such limitations as are justified in a free and democratic society. Section 32(1) of the Victorian Charter of Rights and Freedoms is an example. So too is s 5 of the New Zealand Bill of Rights Act 1990. The question is, are these provisions to be used in defining what the rights mean?
In Momcilovic the minority (French CJ, Crennan and Kiefel JJ) answer was no, s 32(1) is just a mechanism by which the court can decide whether to issue a declaration that the legislation in question inconsistent with the rights. However the majority (and I recall Dworkin's comments on the weights that might be given to individual judge's votes: Justice for Hedgehogs, pp 484-485) did use the rights-limiting provision as interpretive: Gummow J at 166-168, Hayne J agreeing at 280, Heydon J at 411-427, and Bell J at 678. Similarly, but where the New Zealand BORA does not give the courts power to make declarations, s 5 has been held to be interpretive, to be used to determine what the right means: Hansen v R  NZSC 7 per Blanchard, Tipping, McGrath and Anderson JJ (57-60, 89-92, 186, 190-192), but with Elias CJ dissenting at 6, 7, 15-24. The Chief Justice's dissent takes the approach which was favoured by the minority of the High Court of Australia in Momcilovic.
But even this interpretive role in the New Zealand approach is not necessarily applied. For example, in Morse v Police  NZSC 45, discussed here on 6 May 2011, only McGrath J used it.
The interpretive method, outlined by McGrath J in Hansen at 192, applies the following steps:
- Ask first whether the circumstances fit within the ordinary meaning of the statutory provision being applied. Here, which standard of proof would be a natural interpretation of the reverse onus provision?
- Then ask whether, on that meaning there appears to be an inconsistency with a protected right. Here, is the legal burden on the defendant inconsistent with the right to be presumed innocent?
- If there is such an inconsistency, ask whether the limit on the right is a justifiable one in terms of s 5. Here, is the legal burden on the defendant justifiable?
- If the limit is not justifiable, ask whether there is another meaning available through which the statute can be read consistently with the right. Here, can the reverse onus provision be read in a way that puts an evidential burden on the defendant?
- If there is no such other meaning, the natural meaning must be applied. Here, the legal burden on the defendant.
It is well worth reading French CJ's judgment in Momcilovic at 37-51 for a comparison with the approach in applying s 3 of the Human Rights Act 1998[UK], in particular at 49:
The UK interpretive approach is of the third kind mentioned above: some straining for a rights-compliant meaning is allowed (Ghaidan v Godin-Mendoza  UKHL 30 noted here 19 September 2005), the New Zealand and Australian approaches are of the second kind.
And for a wee caustic-to-the-point-of-being-truthful glimpse of how the law works, see Heydon J in Momcilovic at 455.