Expert Speciality and Issue of Contention
When engaging an expert witness, it is of paramount importance that a correct match is made regarding the contentious issue in litigation and the speciality of the expert witness engaged to provide opinion. It is likewise very important that all expert witnesses who provide evidence clearly identify how their “training, study or experience” (s 79 of the Evidence Act 1995 (NSW) relates to their specialised knowledge, and how this specialised knowledge relates to the facts on which they are providing expert opinion.
A Camouflaged Cable?
Hawkesbury Sports Council v Martin  concerned an incident that occurred on community land owned by the Hawkesbury City Council and maintained and managed by the Hawkesbury Sports Council. The plaintiff tripped and fell on a steel cable strung between low timber posts forming a fence that separated a car park area from the playing fields. The fence had been installed in the 1990s to deter cars from driving onto the sports ground areas. Immediately behind that fence, on the same side as the playing fields, was a row of large concrete blocks, each about a metre and a half apart from one another and extending over a distance of around 40 metres.
The plaintiff claimed that the presence of the large concrete blocks had the effect of distracting any individual approaching from being aware of the danger of other obstacles. She also argued that the concrete blocks gave the impression that access could be gained to the playing field by passing between the concrete blocks. The cable blended with the surrounding dirt and gravel. The plaintiff claimed that this, combined with the fact that the cable was under shade, made the cable very difficult to detect.
The defendants argued that the cable was obvious and perfectly visible, and that anyone taking reasonable care for their own safety would have observed it and taken the appropriate precautions.
In the initial District Court hearing, the plaintiff successfully claimed damages against the council in negligence and was awarded $391,415. This amount included a reduction of 30% for contributory negligence, on the basis that, had the plaintiff been watching where she was walking, she would have seen the cable obstructing her path. Expert evidence played an important role in the primary judge’s decision.
The council appealed against the findings of liability on the part of the council, and also on quantum of damages. The plaintiff cross appealed on the finding of contributory negligence.
The Expert Evidence:
Regarding the competing expert evidence presented at the District Court trial, the judge preferred the evidence presented by Professor Alais and Mr Grieve, the experts engaged by the plaintiff. Professor Alais described himself as a “professor of experimental psychology” and an “international expert in visual perception and vision science.”  Mr Grieve described himself as a “building consultant, civil engineer, and lawyer” .
The NSW Court of Appeal found some difficulty with Professor Alais’ evidence, concerning the assumptions he made regarding the viewing conditions of the plaintiff when writing his report, and the assumption he made regarding where the plaintiff, or a reasonable person in her position, would have been looking. However, as the primary judge did not rely on Professor Alais’ evidence, having decided to put “vision [evidence] generally aside”  this was not a major issue in the appeal.
Conversely, Mr Grieve’s opinion, upon which the District Court judge put significant weight, regarded matters of visual perception – namely, whether the cable was likely to be recognised by someone in the plaintiff’s position. Mr Grieve opined that it would have been difficult to spot the grey cable in the “shaded earth and gravel” , and also that the “bulk and size of the concrete blocks tended to attract the attention of the pedestrian and reduced the pedestrian’s ability to detect the cable”.  Mr Grieve did not, at any point in his report, identify the area of ‘specialised knowledge’ that he had gained by virtue of his ‘training, study or experience’ that formed the basis of his opinions regarding the visual perception of the plaintiff. Although laypeople may be able to use their firsthand experiences to comment on whether certain things are visible, this in itself does not form part of the body of “purely specialised knowledge upon which an expert’s opinion depends.” .
Due to this, and due to the fact that Mr Grieve failed to identify and establish the specialised knowledge, based on his training study or experience, upon which his opinions were based, the majority of the NSW Court of Appeal found that the primary judged erred in allowing his evidence relating to visual perception to be admitted .
The majority of the NSW Court of Appeal found that, without the admittance of Mr Grieve’s expert report, the remaining evidence “[did] not establish that the risk of harm caused by the positioning of the concrete blocks and the retention of the cable was not insignificant”, and that the position of the concrete blocks was “plain and obvious.” The absence of any previous complaint of previous tripping incidents also impacted on the court’s decision. The appeal was therefore allowed.
This case is a valuable reminder of the importance of ensuring that an expert’s area of expertise is a match for the point of contention within a case. Due to a failure to ensure this, the relevant expert evidence that was given on the subject was deemed inadmissible by virtue of the expert’s lack of speciality in visual science. Thus, expensive expert comment was rendered inadmissible, and severely weakened the plaintiff’s case.
If you require an expert witness for a legal matter, please click here to make an obligation free enquiry.