Had a strange experience in my last entry into the US myself. I have a Canadian passport, but have a US green card. Officer (in a rather rude tone): "what were

Had a strange experience in my last entry into the US myself. I have a Canadian passport, but have a US green card. Officer (in a rather rude tone): "what were you doing in Canada?" Me (sleepy and a bit disoriented): "sorry?" Officer (suddenly seems to realize that he has my green card in front of him): "Never mind, you're good to go" My best guess is that he was just too conditioned to grasp at straws for reasons to give people a hard time, until realizing he couldn't deny entry to a green card holder.