Originally Posted by
dudestir
My data point is a bit different.
Flew YYJ-YVR-LAX and had put my nexus in for the KTN. I arrived at YYJ and presented my passport at checkin. The agent didn't want to see it (she didn't even take it from my hand) she wanted and only used my Nexus as that's what I had entered online.
This has been my experience at SFO as well.
Several times the checkin agent specifically said they had to re-enter my passport as that was the document being checked at docs check time.