It happens.... but they usually buy you a drink to make up for it
Seriously though what bothers me though is the number of Americans travelling as "Canadians"... you know the Canadian flag displayed and all (in fact I have seen GCs recommend doing this). You should have pride in your own country and not feel the need to hide who you are.... as well as mis-represent yourself to others... to me it'd be like me wearing another org's letters....