Concealed carry permits I think can come up on their systems, perhaps depending on which state issued it. The border agents are permitted to "hassle" most anyone (in the sense of searching through vehicles and so forth) for most any reason; sometimes random searches, sometimes a hunch, sometimes perhaps because it's the first time for the person or vehicle to cross the border and they have no history, etc. I wouldn't be surprised in the least if the attitude of the person crossing came into play as well.
Many people with concealed carry permits cross the US/Canadian border every day with minimal or no hassle. Some people without such permits cross with more thorough investigation. Usually being polite and accommodating and letting the agents do their job results in little difficulty and fairly quick service, of course assuming you aren't actually trying to do something illegal or sneak something through that's forbidden. I have yet to encounter a Canadian immigration official who has been anything other than professional...maybe dreadfully humorless, but always professional and courteous. (I don't mean having a green pepper in the fridge on a day when green peppers are being confiscated, but rather smuggling drugs or firearms or other things of that ilk.)