Progressive said that fact the shop did not happen on the specified date suggested that Nikki was not "a real human person" as indicated in the ad.
Progressive was also concerned the fine print was too small and contained details that may have influenced the way consumers interpreted the ad.
In its response, Foodstuffs conceded it had made an error in referencing the August 7 2017 date on its website advertisement. The correct date of the shop was actually September 28 2017 and this was accurately reflected on the TV and YouTube advertisements.
"Stating the incorrect date in the advertisement was a genuine mistake," said Foodstuffs.
"If Progressive or any consumer had written to us directly, we would have fixed the date immediately."
Foodstuffs said it had since updated its vetting process to ensure errors of this nature do not slip through in the future.
"We have now implemented a two-step checking process," Foodstuffs said.
"While the TV advertisements were checked by the legal team, the website advertisements were not (as they should be an extension of the TV advertisement). Website advertisements will now be checked by the legal team going forward."
Regardless of the error being inadvertent, Progressive said it meant that the figures quoted in the shopping list were not accurate for the day in question.
"It's a very specific advertisement and, in circumstances where an advertiser makes specific claims focusing on the genuineness (or "realness") of a shopper, the content of the shop and the place the shop took place, the actual date of the shop is critical," Progressive said.
In its decision, the ASA accepted the submission that Foodstuffs had made an error on its website and noted its regulatory action to ensure a more rigorous checking system.
Looking at the methodology employed by Foodstuffs in coming to the figures, the ASA panel found that shopping list were representative of a real shopper and consumers would not be misled by the representation of Nikki as a real shopper.
The Panel said the fine print on the video and website advertisements was clear and provided further explanation of the methodology used in the comparison which did not dimish the viewer's out-take of the advertisements.
The ASA panel ruled that the case was settled through Pak'nSave's correction of the error and also rejected Progressive's claims that Nikki was a misleading representation of a real person and that the small print was not clear enough.