It's not really all that unusual that it might happen at a Walmart, considering there are almost 5,000 in the US alone and many 4-5 acres in size, and they are about the largest employer in the US , except for govt.
It's just a likely spot just by volume,....and customers tend to be lower end like much of the merchandise, it's a place frequented by people looking for the low price, low service model.
We all know the quality level of merchandise sold there, they don't pretend to be Sachs5thavenue