It may be a person in a hurry
Haste makes waste. Someone incapable of properly reading a food package, whether due to time, reading, language, or other limitations should not be making purchasing decisions.
Many people reasonably understand that a food item displaying an OU *anywhere* on the front, back or side of the outside packaging implies that all food items contained within said packaging is certified kosher by the OU.
Al zeh gufa anu danin; I don’t think that’s reasonable.