As I said, the actors who represent a proximate threat to most refugees are not state actors. As non state actors, they don't "recognize" citizenship. They are [extremely?] unlikely to know that Canada does not provide protection to PRs. These unsavoury actors are not standing around ports of entry inspecting passports and examining status documents and determining who is under native law and who is protected by foreign actors -- they're violent thugs, and not generally the brightest bulbs in the pack!
As visitors, and not residents, refugees are less likely to be perceived as threatening (e.g., an unwanted, minority ethnicity has, by virtue of "visiting", already been racially cleansed from the area -- they're no longer resident, they're only "visiting"). Further, having "status" in a well respected country, like Canada, may give these actors pause -- they're unlikely to want to be at the centre of an international incident which might redound unfavourably upon themselves.
