Having been the unfortunate victim of standing in a checkout line in a Carrefour store in Urumqi and nearly missing the bus to the airport, I can completely understand how this happened.
It was hot, crowded, miserable, and no one was willing to stand in a civil line. I had stopped in to make a drugstore purchase because we were flying out to Kashgar that day, and I was pretty sure that there wouldn't be a drugstore in Kashgar. The Carrefour was under the main bazaar, and it was more crowded than any supermarket I have ever been in. It took more than a half hour to check out.