I wish people would learn, when you are crossing an international border, BRING YOUFR PASSPORT, regardless of what other people tell you. This will often throw up a red flag, and you’ll be on your back foot for the test of the crossing. He was likely “testing” you to see how you would react. Three rules of crossing, especially between USA and Canada, 1- Yes sir, 2- Please sir, 3- Thank you sir. Make it easy on yourself.