In part I could, without a doubt.
I just came back from the Dominican the night before last, and coming through Toronto airport, I dealt with CBSA folks who were in the building just looking at luggage in a very controlled environment, where people had gone through metal detectors, etc. Even though they're very observant, they're going to be very cautious from all kinds of perspectives, including personal safety, but probably less so than someone sitting at a booth in Cornwall, where people are coming across and are maybe carrying kilos of coke and have the potential of being armed, are trying to escape, etc.
There may be different mindsets, but I think all those who are sitting on a line at Windsor–Detroit, Cornwall, etc., must have that enforcement mindset and that caution mindset. They would have to be always very cautious of what the next person who comes to that line is up to.