This was a dilemma recently faced by John Birdsall at CHOW:
One of your hosts is grilling his famous Yucatan chicken, and in the kitchen, you spot it, smeared with achiote paste, covered in plastic, but sitting out on the counter. It looks like it's been marinating there for a while. It stays unrefrigerated for the couple of hours you drink margaritas and talk, and sits around a while longer after it comes off the grill.
Food has a "danger zone" between 40°F and 140°F; between these temperatures, bacteria grows readily, doubling in number in as little as 20 minutes. Food shouldn't remain at this temperature for more than two hours, or one hour if the weather is hot. But not all home cooks knows this, or some know and just don't care — either way, a guest who notices the problem is faced with the choice between an awkward encounter with the host or potential illness.
Birdsall chooses to keep quiet with his host, but regrets the decision when he comes down with symptoms of salmonella poisoning about 48 hours after the meal. "You totally should have said something," he tells himself. "You totally should have been that guy."
Read more: Should You Tell Your Host He's About to Poison You? at CHOW
Would you have spoken up and been "that guy" in a situation like this?