it usually clearly says on the job posting that you must be legally entitled to work in Canada. Which implies, PR or Citizen. They won't hire you with just a work permit because, they expire! Plus, is appears he 'could' work legally but doesn't have the visa to start with. This will go no where but is a complete waste of everyone's time. Not be legally able to work in Canada isn't discriminatory, it's just the way it is buddy. This job is posted in Canada for Canadians and you ain't a Canuck!
That's the main problem with these kinds of cases. No matter how stupid they are you can bet your last dollar and win that common sense inevitably loses.