While true, it requires proper food safety precautions and still bears e coli risk. With beef, the bacteria stay on the surface of the muscle. A steak that is seared outside and rare in the middle has still been sterilized by the searing. That aspect goes away with ground beef, where the former surfaces get all mixed in together. When eating a raw minced beef dish like carpaccio or tartare, the proper prep is to remove and discard the outer surface of the steak before mincing in a clean work area and serving immediately. So, in short, eating a medium hamburger patty holds a fair amount more e coli risk than a rare steak.