Taco Bell E. Coli

So the green onions may not the only thing wrong with Taco Bell food. Recently, 64 people have gotten sick [E. Coli] from Taco Bell food. They thought it was the green onions. But over the weekend, the same samples were tested as NEGATIVE for E. Coli. Also, white onions have been tested for E. Coli and came up POSITIVE. Apparently the samples of white onion that came up positive, was mistaken for GREEN onions. How does that even happen, I ask you? In the words of South Park, "I'm not an R-tard." Anyways. The strain that was identified in the white onions, isn't the same as what the people who got sick, had. I dunno. Sounds like a game of Clue.