I had a strange occurence happen to me at YVR customs one trip back in December '12. I was traveling with a non status, and I had booked my companions ticket on my points. So of course at check in the agent tried to charge for the 'non status' bags. A quick diversion to the Concierge created bag tags in my name for the other bags as well. Knowing that all bags were tagged under my name I proceeded through the automated customs with the thought that I'd just indicate that I had 3 bags instead of 1. But for some reason the bags came up under their respective bag owners names on the automated display. I was sure to check the name on the tags upon arrival, and sure enough they were all in my name. How could the automated bag system at customs had known they were different people?

I never have figured that out.

^^^ agree

On the same detour of bag-tagging weirdness (sorry, OP), I have never figured out how generating a boarding pass in Mr. Flyquiet's name generated a bag tag with a perfect stranger's name. We didn't notice until the whole episode was over and we were searching for explanation. And because said stranger was not, in fact, on the flight, the entire flight was delayed an hour while they first searched for him, then offloaded the bag. Obviously the system is capable of storing the bag owner's name separately from the checked-in seat-holder. But why?

Agents trying to charge non-status pax for bags when you're travelling with them is incredibly frustrating, as you have every right to check in up to 3 bags. I would hold my ground and say "all 3 bags are mine".

The latter has happened to Mrs. YVR as well. I think when you pass your bags through to the luggage carousel (just before security) and they scan individual boarding passes - that's where a bag gets assigned to the owner.

Yep. I simply and clearly state right off the bat that all bags are mine.

Of course, I make sure with my companion that what they packed was in good standing ahead of arriving at the airport.