My reading of the article is that it's legal to serve undercooked beef as long as (a) you warn the customer and (b) it doesn't happen to contain E. coli. But s

My reading of the article is that it's legal to serve undercooked beef as long as (a) you warn the customer and (b) it doesn't happen to contain E. coli. But since you can't ensure (b) you may be breaking the law without realizing it.