First, there is an asymmetry in power too. Amazon can afford to double check or triple check everything if it makes economic sense.
Secondly, companies does not have morals. If you allow big corporations to change prices as they see fit because there is a "mistake". Companies will exploit that to their advantage with psychopathic precision.
You will get your package at home and then you will be informed that the price "was a mistake" and was 10% more expensive. They will print prices in adverts and then say that it was a mistake when people gets to the shop.
Companies are not human beings, as other comments already have said, to involve morality in this issue makes no sense whatsoever.
The real question is: is this an efficient way of improving the consumers well being? If this rules avoid companies of abusing price changes and labeling anything as being a "mistake" and at the same time it encourages better quality on price setting and the "punishment" is not big enough to send all companies to foreclosure. Then it seems a very good deal.
It makes economic sense.