I had the following email exchange earlier this year with a concerned client:

Client (in late January 2013):  "Hi Steve, I was wondering if you knew of any cases where employees were prosecuted for not following federal regulations regarding food safety or for falsifying documentation regarding food safety? I am looking for examples of situations where employees were held accountable. Any help that you might be able to give me will be greatly appreciated. Thank you in advance for your help."

Me (later that day in January): "It's HIGHLY UNCOMMON for employees to be prosecuted for not following federal regulations regarding food safety. For example, the President and the Plant Manager of The Peanut Corporation of America (the folks responsible for that HUGE peanut recall three or four years ago that KILLED several people), who allegedly knew (internal documents showed it) that their products were contaminated with Salmonella, but decided to ship them anyway, have NOT been charged criminally under the federal regs (although there continues to be a criminal investigation, apparently).  That's an egregious case, and they're not in jail.

"That said, I think that it would not be unusual for an employee who INTENTIONALLY contaminates a food product (which is different than not following food safety rules) to face criminal charges. I'm sure that there are examples of that – although none come to mind right now. Also, there is an old legal doctrine (from 1970's) called the Park Doctrine. This can be scary for owners and officers of food companies. It says, essentially, that the FDA/DOJ can bring criminal charges against company officials for alleged violations of the federal Food Drug & Cosmetic Act  - even if the corporate official was unaware of the violation – if the official was "in a position of authority to prevent or correct the violation and did not do so". This is a rarely used "tool", but the FDA in recent years has suggested that it will be using it more frequently in its efforts to keep the food supply safe."

Client (later that same day): "Great. Thanks for the feedback. Who'd guess that the PCA guys would go free?"  

Me (two months later): "I hope this message finds you well. I wanted to follow-up to my prior message with an update. Strangely enough, only shortly after my response to you, the US Dept of Justice did charge four individuals, including PCA's owner and president, in a 76-count indictment (and another employee pled guilty) stemming from the 2009 Salmonella outbreak involving the Peanut Corporation of America (and its allegedly filthy facilities). So, I spoke too soon in my prior email (too soon by about 3 weeks )."

This is another clear example of FDA, although it took them a couple of years, being very serious about food safety and using its enforcement tools in a way to make industry take notice.