I think the "pork and beans" doctrine applies here. You'll recall that it was first articulated by His Eminence, Eustacius Cardinal Van Camp, at the Second Council of  Cibus in 1397.

"Yea, verily, shouldest any of the faithful inadvertently consume some portion of meat or meat by-product in a dish otherwise intended to be meatless, they shalt not suffer the pains of eternal torment."