Not only is it an offence in Canada to drive while impaired or over the legal limit, it is also an offence, of equal consequence, to refuse to provide samples of your breath, even for screening purposes.
I was counsel at trial and on the appeal on an allegation of refusing a roadside demand. The decision of Hebner, J. is found at R. v. Drouillard, 2018 ONSC 4295 (CanLII). The case involved a roadside demand made when the driver was seated in her vehicle. The entire demand process was recorded by a video camera worn by the police officer making the demand. The officer felt that the subject was not making a genuine effort in any of the seven attempted blows and, for that reason, she was charged with a refusal. Perhaps curiously, in this three-minute interaction, after the fourth try, she made a statement refusing to co-operate further. She was however offered another opportunity which she accepted.
The trial judge found essentially that the offence was completed at that point. The appeal court disagreed and determined that the whole exchange had to be seen as one transaction. Justice Hebner ruled that, because there was no evidence about the machine itself, it would be difficult to conclude beyond a reasonable doubt that the subject was really refusing.
She was acquitted on the appeal.