In DHL Supply Chain (Pty) Ltd and Others v National Bargaining Council for the Road Freight Industry and Others  9 BLLR 860 (LAC), the Labour Appeal Court (LAC) (per Sutherland AJA, Ndlovu JA and Molemela AJA) held that the mere fact that an employee fails a polygraph test is not in itself sufficient to find an employee guilty of dishonesty. Also, that the employer is required to lead expert evidence to prove cogency and reliability of polygraph tests should the employer wish to rely on the results of a polygraph test.
In this case, the employer had experienced stock losses in its cigarette dispatching warehouse and required the eight employees who had been working in the warehouse at the time of the stock losses to undergo polygraph tests. Two of the employees failed the polygraph tests and were charged with theft in an internal inquiry. The employer alleged that during the inquiry the employees were not credible and were consequently dismissed. The two employees referred an unfair dismissal dispute to the bargaining council, the outcome of which was that their dismissal was found to be substantively unfair and they were reinstated. The employer instituted review proceedings in the Labour Court but the review application was dismissed. The employer then appealed to the LAC alleging that the evidence demonstrated that the employees were guilty of theft and alternatively, that even if their dismissals had been unfair, reinstatement was not an appropriate remedy and compensation should have been ordered instead.
The commissioner had disregarded the evidence of the polygraph tests and found that the mere fact that the employees had been on duty when the theft occurred, had access to the stock and the stock losses ceased after their dismissal was not sufficient to find them guilty of theft. The LAC considered case law in which it was held that polygraph evidence can be sufficient to discharge the onus in labour disputes if it is not in isolation, but there is also other circumstantial evidence to support the finding that the employees are lying. In light of this, the LAC found that the commissioner had not acted unreasonably in failing to take into account the results of the polygraph tests as in light of the other circumstances surrounding this matter there was not enough evidence to infer guilt from the results of the polygraph tests. The circumstantial evidence that the employer raised was the fact that the stock losses had stopped. However, this was not sufficient as there were other possible factors to account for this such as tightened security or the fact that the real thieves may have decided to lie low.
It was found that the results of polygraph tests are not in themselves sufficient to establish guilt. The LAC noted further that the weight to be given to polygraph tests remains an open question but in the event that a party wishes to rely on them it would need to produce expert evidence on the accuracy of the polygraph test and why an inference should be drawn from it. The LAC found that no expert evidence had been given in this case on the concept of polygraph testing or on the technical integrity of the process. It was found that submissions by the operator of the polygraph machine did not amount to expert evidence because the operator lacked independence and sufficient credentials.
As regards the order of reinstatement, the employer argued that there had been a breakdown in the trust relationship and that even if the employees were not found guilty of theft the taint of suspicion was enough to undermine the employment relationship. Sutherland AJA considered the discretion that arbitrators are afforded by the Labour Relations Act 66 of 1995 in granting reinstatement or compensation and found that the default remedy is reinstatement where the dismissal is substantively unfair. It was found that where there is not sufficient evidence to prove that an employee is guilty of dishonesty then that employee should not be deprived of employment unless continued employment is intolerable or impracticable. The LAC also considered the element of consistency and the fact that previous employees had failed a polygraph test but had not faced dismissal as there had been no other evidence to support a dismissal.
Reinstatement was accordingly found to be the appropriate sanction and the appeal was dismissed.