Government's Flexible Definitions of Risk

I'm still trying to come to terms with what the term "risk" actually means to the government.

In today's Washington Post, there is a story about the Agriculture Department prohibiting the use of beef from so-called "downer cattle" in federally funded school lunch programs, but it also allows the beef under certain conditions to be sold to the general public. As the article notes, this disparity seems to undermine Agriculture's claims that there is no food safety reason to ban meat from all cows too sick or injured to stand.