What are the implications of the phrase "A discharge under this section shall be deemed to be an acquittal": s 347(4) Crimes Act 1961[NZ]?
Does it imply that there should be deemed to have been a verdict of not guilty? And that evidence had been adduced that was sufficient for a fact finder (jury usually) to consider? And that the evidence that the prosecution had adduced at this notional trial had been the strongest that had been anticipated on the basis of pre-trial proceedings?
Or does it simply mean that when the judge told the accused "You are discharged" he meant "You are found not guilty without the need for a trial"?
A difference in understanding of the meaning of "deemed" in this context, where its implications for the special plea of previous acquittal (s 358(1)) had to be determined, was the basis for a difference of opinion in the New Zealand Court of Appeal: R v Taylor  NZCA 558 (17 December 2008).
The majority (Chambers and Panckhurst JJ) in separate judgments placed slightly different emphasis on grounds for their conclusion that where s 358(1) mentions a "former trial" it means an actual trial, not a notional trial that was deemed by s 347(4) to have occurred.
Chambers J at 39 set out his reasons for declining to give "former trial" an expansive meaning. Each of these may, with respect, be challenged. He said an expansive meaning would strain the wording of the subsection, that he didn't know how the subsection should be re-written, that the same expanded meaning would have to apply in s 358(2) and 359(3), so that and revision of the law would have to be legislative. In answer to those propositions it could be said that there is no straining other than that required by the deeming provision, that no rewriting is required, and that the phrase "former trial" need not have the same meaning every time it is used but can take its meaning from its context.
Panckhurst J focused on the common law origins of the legislative provisions on the special pleas, holding (116) that there is an underlying requirement of jeopardy of conviction. Consequently, "former trial" means an occasion on which the accused was at risk of conviction (117), and that a deemed acquittal does not trump the requirement of actual jeopardy (123).
That, of course, assumes that the legislature did not intend to deem a former trial to have occurred.
Fogarty J dissented on this point. He held (134 – 138) that the deeming provision should not be read down, but instead should be given a liberal interpretation so as to mean that there was deemed to have been a trial prior to the proceedings at which the special plea is made. Parliament intended that a discharge under s 347 should carry all the benefits of an acquittal (139). This removes any apparent inconsistency between the sections (141).
There are attractions in the reasoning of the dissent. An interpretation that avoids legislative inconsistency is preferable to one that requires the legislators who enacted the Crimes Act 1961 to be thought of as fools whose efforts were "curious and archaic" (25).
No doubt the unsuccessful (self-represented) appellant will be drafting his application for leave to appeal to the Supreme Court. On the assumption that these proceedings are not yet at an end, I say no more.
[Update: the Supreme Court refused leave to appeal: Taylor v R  NZSC 45 (15 May 2009), saying that "whatever may be the answer to the s 347 point" the proposed appeal had no prospect of success because the offences were not sufficiently similar to permit the plea of previous acquittal on the facts.]