To prove or not to prove? Novus actus interveniens in third-party claims

December 1st, 2018

Van der Merwe v RAF (GP) (unreported case no 42358/15, 16-3-2018) (Ranchod J)

By Tshepo Mashile

Novus actus interveniens is a Latin legal phrase, which describes an important principle in criminal and civil procedure in as far as causation and liability is concerned. Loosely translated it means ‘new intervening act’.

Ranchod J, in the Gauteng Division, Pretoria had occasion to deal with this principle in a third-party claim in this matter.

The facts in brief

The plaintiff, Amore van der Merwe was injured in a motor vehicle accident on 27 October 2012 in Modimolle, Limpopo Province. She was a passenger in a motor vehicle, which slid backwards on an embankment, capsized and rolled over her. She was on holiday in South Africa when she was injured in the accident.

Liability was admitted by the Road Accident Fund (RAF) and the only triable issue was the issue of the quantum of the plaintiff’s damages.

The RAF admitted the correctness of the medico-legal reports from the various experts of the plaintiff. Only the evidentiary value of the reports was challenged.

The plaintiff was 19-years-old at the time of the accident and 24-years-old at the time of the trial. Her legal representatives were of the view that it was not necessary for her to testify at the trial as the trial related to the quantum of damages only. The defendant was, however, of the view that she should be available to testify. It was agreed by both parties and arranged that she testify via Skype as she was in New Zealand.

It was her testimony that her hip was causing her great discomfort and that she had been unemployed due to the injuries she sustained in the accident. She stated that she would like to study and work in the future, but was not able to do so due to the injuries.

An educational psychologist and an occupational therapist testified after her. There was no cross-examination of the plaintiff or the two experts by defendant’s counsel and the plaintiff closed her case. The defendant did not lead any evidence and closed its case as well and both parties presented their arguments.


The thrust of the defendant’s argument was that the plaintiff had suffered further injuries on 8 October 2015 when she fell from some stairs and sustained injuries to her right knee and lower back. This, argued counsel for the defendant, constituted a novus actus interveniens for which the defendant could not be held liable as far as the injuries the plaintiff sustained in the fall were concerned. The fall and the injuries sustained were revealed for the first time in the medico-legal report of the plaintiff’s industrial psychologists dated 1 March 2017.

All the plaintiffs’ medico-legal reports were obtained after 8 October 2015, namely between 3 November 2015 and 1 March 2017. The defendant argued that the plaintiff’s experts did not differentiate between the injuries sustained in the motor vehicle accident and those that she sustained as a result of the fall.

The defendant’s counsel submitted that the plaintiff had the option of asking for a postponement with a tender for costs in order to allow her experts to re­write their reports and exclude the later injuries. Alternatively, that the court should grant absolution from the instance.

Firstly, the plaintiffs’ counsel submitted that the defendant’s entire argument on this score stemmed from one passage in the industrial psychologist’s medico-legal report. Secondly, the argument went, the defendant’s counsel had failed to cross-examine the plaintiff and her two experts hence the defendant could not raise the issue of a novus actus interveniens. Thirdly, the defendant had not raised a substantive defence of novus actus interveniens and had not adduced any evidence in that regard. Finally, the onus of proving a novus actus rested on the defendant.

In the court’s view the above submissions could not be sustained. The fact that the plaintiff sustained further injuries almost three years after the motor vehicle accident was peculiarly within her knowledge. It appeared that she had been to an orthopaedic surgeon on 13 November 2015 about three weeks after she fell on 8 October 2015, yet no mention was made of the fall to him. One can only assume that she did not mention it to the orthopaedic surgeon. The same can be said about her visits to the other experts. She consulted the industrial psychologist on 4 November 2015; a neurosurgeon on 3 November 2015; a plastic surgeon on 13 November 2015; an occupational therapist on 14 November 2015; a neuropsychologist on 3 June 2016 and the educational psychologist on 22 February 2017. None of them, except the industrial psychologist, indicated that the plaintiff had told them about the fall on 8 October 2015.

The result was that all the plaintiff’s experts took the injuries she sustained in the fall from the stairs into account when compiling their reports and forming their opinions. The defendant could not have been expected to do anything about that.

The onus was on the plaintiff to prove causation, which, in the court’s view – given that it was peculiarly within the plaintiff’s knowledge that she fell and sustained injuries – also meant to exclude any interruption of causation.

The plaintiff carries the burden to prove causation and where the plaintiff has sustained further injuries after the accident there is a secondary burden on the plaintiff to prove that the causation of such injuries does not interrupt the causation of all the injuries that the plaintiff presents with. By failing to disclose that there are injuries which she sustained when she fell down the stairs (a fact which was always within her knowledge) the plaintiff gave the experts the impression that all the injuries she presented with were caused by the accident and they, therefore, treated all injuries as such. The experts should have, therefore, been briefed of the fact that the plaintiff had fallen down the stairs in order to enable them to exclude these injuries from their opinions.

The aforesaid reasoning is so because the experts should be able to say that the plaintiff fell because of the injuries sustained in the accident. In this way, the injuries would not be regarded as a new intervening act. But by presenting all the injuries as if they are caused by the accident, the plaintiff was misleading the experts and, therefore, her claim cannot be said to have been properly quantified because she has failed to show that all the injuries are accident related.


Causation includes two distinct inquiries – factual and legal. Factual causation relates to the question whether the defendant’s wrongful act was a cause of the plaintiff’s loss, and is generally referred to as the sine qua non (‘but-for’ test), namely, what probably would have happened but for the wrongful conduct of the defendant. However, even if it was shown that the wrongful act was the sine qua non of the loss, it does not necessarily result in legal liability. The second inquiry must then take place, namely, whether the wrongful act was sufficiently closely or directly related to the loss for legal liability to arise or whether the loss is too remote. This is called ‘legal causation’ (see International Shipping Co (Pty) Ltd v Bentley 1990 (1) SA 680 (A) at 700E – G, 700H – 701D and Minister of Police v Skosana 1977 (1) SA 31 (A) at 34E – 35A, 43E – 44B).

In considering legal causation, a factor, among others, that is taken into account is the absence of a novus actus interveniens. In this case, the plaintiff herself told the industrial psychologist about the fall and the injuries she sustained. This fact had become part of the factual matrix the court had to consider in determining the plaintiff’s quantum of damages.

There was no onus on the defendant to prove the extent of the plaintiff’s injuries and their sequelae with regard to the fall. The plaintiff proved all the orthopaedic injuries contained in the expert reports, including the two injuries constituting the novus actus by confirming them in her testimony at the trial and the admission of such evidence by the defendant when it admitted the content of the expert reports. The defendant does not attract an onus to prove the novus actus as a substantial defence in these circumstances.

There was no primary fact evidence presented by the plaintiff to link the two injuries constituting the novus actus to the motor vehicle accident. It is for the plaintiff to prove her loss without taking the novus actus into account.

It was also contended by her counsel that her fall was foreseeable and an inherent risk in the post-accident condition. The onus was on the plaintiff to prove these two allegations.


Much store was put on the defendant’s failure to cross-examine the plaintiff and her two witnesses. The defendant did not have to because it was accepted that two sets of orthopaedic injuries existed, those sustained in the motor vehicle accident and those sustained in the fall. The defendant did not have to call any witnesses to prove the novus actus – the plaintiff had to do so.

The court was unable to determine the plaintiff’s quantum in respect of the injuries sustained in the motor vehicle accident on 27 October 2012 and ordered an absolution from the instance of the plaintiff’s claim with costs.

Tshepo Mashile LLB (UL) is an attorney at Mkhonto and Ngwenya Inc in Pretoria.

This article was first published in De Rebus in 2018 (Dec) DR 33.