Are boxes matched to the receipt?

[iMassguy]

I was reading on one of the forums (can't find the post) that someone bought a WiFi version of the iPad and ended up with an AT&T. I guess they handed him the wrong one which is a good thing for him. I mentioned this to a friend that used to work at a major retailer. She said that boxes are usually scanned and that item is then married to the receipt. The serial number or other identification would be listed on it. I thought the same thing. Either way, I guess it was nice to end up with an AT&T pad and only pay for WiFi.