Scientific or technical knowledge defence


In a high-profile decision handed down in April 2012(1) the New South Wales Supreme Court decided that KFC was liable for a plaintiff's severe brain damage resulting from encephalopathy caused by salmonella food poisoning from a 'Twister' chicken tortilla. The plaintiff's other family members were also poisoned but their complications were much less severe.

Most of the reasons for the decision were occupied with a complex fact-finding exercise. That said, two matters of potential significance may be noted for other product liability proceedings. Together, they suggest that stringent product safety procedures may be less useful to defendants in avoiding product liability than might be expected.


The decision illustrates that evidence of stringent procedures to ensure product safety can be of little assistance in establishing that a defect in the product did not cause the relevant damage.

Unusually, KFC was found liable despite trial judge Justice Rothman finding that "the likelihood of KFC being the cause of this injury [was] remote and the occurrence [of salmonella poisoning from KFC food] generally highly improbable".

Rothman said that in the ordinary course, and assuming compliance with KFC procedures, it is effectively impossible to contract salmonella from KFC. Further, he said that "if there were another reasonable possibility" then he "could not be convinced, even on the balance of probability, of the liability and responsibility of KFC".

Rothman decided that there was no other reasonable possibility because he found that the only item of food consumed by all persons who contracted salmonella was the Twister. Rothman reached this decision despite noting that a court must conclude both that a certain version of the facts is more likely than not, and also that the material before the court is appropriate to make that finding of fact. The material that Rothman relied on was two-fold. First, he accepted the evidence of a single family member that she threw out a portion of food given to her by her family rather than consuming it. Second, he found that there was some non-compliance with KFC procedures at the relevant store, though there was no direct evidence that there was non-compliance in respect of the Twister in question.

Scientific or technical knowledge defence

The decision suggests that the more stringent and effective a defendant's product safety procedures, the more difficult it is for the defendant to avail itself of the scientific or technical knowledge defence to statutory defective goods actions. This defence is available if it is established that "the state of scientific or technical knowledge at the time when the goods were supplied by their manufacturer was not such as to enable that safety defect to be discovered".

The defence has previously been established if testing was not possible because it was necessary to destroy the goods to test them for a defect.(2) On one view, that could apply to a salmonella-contaminated tortilla, since to test the whole tortilla for contamination, it would necessarily be destroyed (poisoning can occur merely by ingesting enough salmonella cells to occupy a pinhead).

However, the court considered (albeit briefly) that the defence was not available for the following reasons:

  • it is near impossible to contract salmonella from a KFC product if KFC's procedures have been followed;
  • it follows that if salmonella is contracted from a KFC product, KFC's procedures have not been followed; and
  • the fact that KFC's procedures were not followed is something within KFC's knowledge, at least through the knowledge of the employees responsible for following the procedures.

For further information on this topic please contact Moira Saville or Duncan Campbell at King & Wood Mallesons by telephone (+61 2 9296 2000), fax (+61 2 9296 3999) or email ([email protected] or [email protected]).


(1) Samaan bht Samaan v Kentucky Fried Chicken Pty Ltd [2012] NSWSC 381.

(2) Graham Barclay Oysters v Ryan [2000] FCA 1099, a case involving contaminated oysters.