Having been an independent floor trader leasing a full membership I can tell you from first-hand experience that the quality and veracity of the prints is incredibly important.
The NFA enforcement files are full of cases where people get fined, banned, sanctioned for bogus trades. There are cases where floor brokers intentionally printed false prices to fill customer orders into other brokers working the filling broker's spec account. Outright stealing.
It was a fairly common occurence that when a price got printed that was hard to believe or any way in doubt, the floor brokers and the pit officials (called 'radio' in the bond pit) went crazy nuts to find out who actually traded that price. The brokers would actually stop quoting markets until the issue got resolved. Many of the prints actually got pulled.
Reason? Because all of those brokers and their floor clerks are holding decks of orders that are triggered by price levels. Floor brokers will lose customers, lose jobs, get sued, all sorts of bad things - if an order does not get filled or gets filled because of a bogus price print. It is a very huge deal.
So, in the scheme of things ConAgra got exactly what they deserved for the cuteness. And I'm sure that ConAgra's bank account and the nice roundness of that $100 figure really hurt their cause.
IMO just another of the many reasons why for all it's foibles electronic trading is light years more compliant and ultimately fair than open outcry.