It's a question for Professor Hogg in regard to Ladouceur.
Of course, in terms of the context of Ladouceur, it was a case of a roving stop in which a police officer asked if the driver's papers were in order, asked for a driver's licence, insurance, etc., and didn't have any suspicion that the driver was in any way acting unlawfully. In that decision, the majority did find a section 9 violation, but it was saved on the basis of section 1. In so finding, Justice Cory and the court stated, in a majority, “Any further, more intrusive procedures could only be undertaken based upon reasonable and probable grounds.”
In the case of mandatory breath testing, it would certainly be much more intrusive to obtain a bodily sample than to simply ask whether the officer can check their driver's licence.
How do you square that statement of the court with the opinion you have reached, which is that this would be upheld under section 1?