Well, we do know that in this case shit __doesn't__ just happen. The sources has to be from somewhere. And we do know factory animal farms have plenty of unsavoury byproducts.
I agree. Can't jump to conclusions. Even so, if feels like a preventable accident that's eventually going to happen (if it hasn't done so already). The ag industry is a strong lobby. Given that those animals need feed there's a clear incentive for all involved to keep the truth from coming out.
I'm throwing out my lettuce like CDC told me to, but I woundn't go pointing fingers on twitter just yet. :)