There is a common misconception by many motorists that if they “do the right thing” and try to “sleep it off” either in the parking lot or at the roadside that they are immune from prosecution….
Unfortunately, this is not the case because it is also considered a crime to be “in care and control” of a vehicle either when impaired or over 80.
An individual is “presumed” to be in care and control of a motor vehicle “where it is proved that the accused occupied the seat or position ordinarily occupied by a person who operates a motor vehicle”. This presumption applies UNLESS “the accused establishes that the accused did not occupy that seat or position for the purpose of setting the vehicle… in motion”.
In order to rebut this presumption, typically a person will have to testify, leading evidence of an alternative intention of entering the vehicle such as waiting for a friend to pick them up or using the vehicle for warmth until some alternate means of transportation is available such as a taxi.
There are also potential defences arising out of scenarios which involve “no risk of danger” and “inoperable vehicles” but this area of the law is very technical and you will need a counsel well versed in defending DUI cases to ensure a successful resolution.
There are a number of defences to the charge of being in care and control of a motor vehicle including: “no risk of danger”, “the alternate plan”, and “inoperable vehicle”; however, every case is unique and will impact which defences are available.
For a comprehensive review of this technical area of the law and a winning argument please see my reported case of R. v. K.M.  O.J. No. 3061 [link]