Constructive Knowledge is another legal principle often invoked in cases of foodborne illness. The law views an operator responsible not just for what he or she actually knows, but what they should have known, discovered or perceived. In other words, ignorance is no defense. If you should have known, the law will assume that you did know. For instance, if an employee spent a vacation in an area where hepatitis is endemic, the operator can be liable under constructive knowledge if the employee causes an outbreak of Hepatitis A. The operator should know the health risks posed by his/her employees at all times.
Given these two legal doctrines, restaurant operators cannot assume that there are legal defenses available to them if an outbreak occurs. Their best efforts should be focused on the prevention of foodborne illness.
If someone becomes ill as a result of eating food you prepared, liability will almost always attach. However, financial judgements and settlements are also influenced by the degree of diligence or negligence an operator has displayed in their food safety operating practices. Being diligent not only reduces the risk of a foodborne illness outbreak but can also mitigate the financial burden should one occur.