i'm having a hard time believing that something in a sealed container that has been heated to boiling temperature for half an hour can contain ANYTHING living.
and, after doing a bit of reading, the bacillus does not exist *within* the rice, but rather can contaminate foods left exposed to open air. it is liked to fried rice because it is likely to thrive in a food preparation business, the same way that you are more likely to find MRSA in an hospital and not in my house.
Bacillus cereus ... have been known to colonize distilled liquors and alcohol-soaked swabs and pads in numbers sufficient to cause infection.
you better get rid of all them whisky bottles you have lying around.
the rice cooker lid seals hermetically. if you open it, add vinegar, then close it, and your food gets infected with bacteria, you need to clean your kitchen.
obviously, your mileage may vary. it depends on where you live, what your average daytime temperature is, and .. how clean is your kitchen. i just speak from experience, i have never refrigerated pickles, mustard, bread, eggs, ketchup, heck, i knew a guy who didn't refrigerate his mayonnaise. my parents didn't refrigerate these, the people i know in my country don't refrigerate these, and we never get sick.
i mean, don't get me wrong, you *can* get sick from old food. but 2% of reported cases are due to this, and my guess is that the majority of these come from a dirty chinese shop where they are infested with bugs .. which i would know something about, having worked in the catering business.