One of the limitations of only looking at the decisions of the senior appellate courts is that sometimes first instance decisions that perfectly illustrate significant principles are missed.
On a charge of refusing to supply a sample of breath, the judge found (14):
"I am satisfied on balance that the accused had been fully cooperative with Officer Renaud and had unhesitatingly agreed to provide a roadside sample. I find that when he exited his vehicle to do so, he was thereupon immediately handcuffed by Officer Renaud and pushed towards the police vehicle, approximately fifty feet away, and shoved into the back while handcuffed. During the process of placing him in the back of the police vehicle, the brim of the accused's hat was pushed down low onto his forehead, thereby impairing his vision other than in a downward direction."
Three independent reasons supported dismissal of this charge: insufficient grounds for requiring the breath sample, reasonable excuse for refusal to provide the sample arising from the improper use of handcuffs, and – of particular interest here – a breach of s 7 of the Charter, concerning liberty and security of the person, which constituted grounds for excluding the evidence of the defendant's refusal to supply the sample of breath.
Here there was a causal and temporal connection between the unlawful arrest and the refusal to supply the sample. It is clear that if, on different facts, there had been no causal connection but only a temporal one, the evidence could still have been excluded: R v Wittwer (blogged here 6 June 2008). An illustration would be where the improperly handcuffed driver continued his cooperation with the procedures, as occurred in the New Zealand case Police v Chadwick  DCR 880. The handcuffing did not cause the evidence to be obtained, but there was a temporal and contextual connection.
I have discussed Wittwer and Chadwick in Misuse of Drugs at para 1300, as follows:
"The exclusion of evidence that was obtained improperly is now governed by s 30 Evidence Act 2006. Other provisions of the Act are concerned with exclusion of unreliable statements: s 28, and exclusion of statements influenced by oppression: s 29. Those provisions operate when there is a causal connection between impropriety, or a source of unreliability, or a source of influence of oppression, and the obtaining of the challenged evidence. Outside of such causal nexus, the public policy discretion is likely to remain: s 11 Evidence Act 2006. Occasions where there is a nexus, other than of a causal nature, are where there is a temporal or contextual association between an impropriety and the obtaining of the evidence, as illustrated in R v Wittwer ... . In Police v Chadwick  DCR 880 the charge of driving with excess blood alcohol was dismissed because of improper use of handcuffs after the defendant had failed a breath test, but before the blood sample was taken; here the impropriety did not cause the obtaining of the blood test result, as the defendant was "co-operating to the full" (para 15), but it was sufficiently serious – illegal, unreasonable, and in breach of s 23(5) New Zealand Bill of Rights Act 1990 - for the evidence to be excluded and the charge to be dismissed on policy grounds. This conclusion was reached upon consideration of Shaheed[ 2 NZLR 377; (2002) 19 CRNZ 165]... . If Chadwick had been decided after the commencement of the Evidence Act 2006 it would still be a case of contextual impropriety, not within the scope of the Act, where the public policy discretion involved a balancing exercise that is essentially the same as that which is provided for in s 30."
Ogertschnig illustrates how lawful resistance to improperly imposed restraint can result in exclusion of evidence, and Chadwick illustrates the common law exclusion of evidence tainted by impropriety, a remedy that should continue to exist notwithstanding the enactment of the discretion to exclude evidence where there is a causal connection between the impropriety and the obtaining of the evidence.