I know that when I found my 4 pair of socks. I never found more than one pair in a bin. Not that people could not have mixed them in the diffrent bins. When I went to target and bought the first two waves of $1 items. For the most part when I would look 90% of what was there was Smurf stuff. And when I did find something in the wrong bin most of the time it was the bin below.
I have witnessed kids picking up something and walking over to the parents to ask if they could have it. The parents said no come on and the kid would just put it in the nearest bin.