“and has been passed up by taxis as he waits on the curb.”
How would he know?
I assume he’s not completely blind, but blind enough to need a dog and be unable to drive. I’m not sure what cabs look like in B.C., but in NYC, for example, they’re all school-bus yellow and would be very hard to miss if you had any vision at all.
His ski instructor dog told him.
How would he know?
Guide dog organizations give each blind recipient several weeks of training (at least The Seeing Eye, in Morristown, NJ does).
Included in this training is recognizing the sound of cars, recognizing patterns of vehicle movements, etc.
So it's likely the man would be very attuned to the way taxis move about a taxi stand, especially if he travels a lot.
He also probably could hear people down the line from him getting picked up, as they spoke with the cab drivers and put their luggage in the cab.