"Aflatoxins can be produced in stored agricultural crops such as peanuts, but do not partition into the oils, acids, or glycerides. Manufacturers were cautioned to make certain that the oils, acids, and glycerides are free of aflatoxins and protein"
"Hepatic changes were noted at microscopic examination of rats fed diets containing 15% edible Peanut Oil for 28 days"
this is a concern, but 15% seems to be a high dose, and it does not specify what kind of hepatic changes. And it does not link the changes to aflatoxin in this study.
So I will not base my decision on peanut oil on this study.
And the common sense way to look at this: Aflatoxin is a well-known toxin closely related to peanut, so it will be a QA priority for the manufacturers. If peanut oil becomes associated in the consumers' mind with unsafe amount of aflatoxin, most people will not buy it and the manufacturers go out of business. It makes economical sense for the manufacturers to watch over it.