CAUTION REGARDING EXPERT OPINIONS ON VISUAL PERCEPTION
July 17, 2019
Hawkesbury Sports Council v Martin  NSWCA 76
The respondent, Ms Apaula Martin, sought damages in negligence against Hawkesbury City Council and Hawkesbury Sports Council (the Councils). Ms Martin tripped and fell on a steel cable strung between low timber posts (essentially, a cable fence) that separated a car park from the playing fields at Deerubbin Park in Windsor. Immediately behind the cable fence was a row of large white or light grey concrete blocks. Ms Martin’s case was not that the cable fence was itself dangerous, but that when the row of concrete blocks was later added, it had the effect of distracting the attention from the continuing presence of the steel cable. That is, the positioning of the concrete blocks created the impression that access could be through one or more of the gaps between them, and the shading from overhead trees and the similarity between the colour of the cable and the brown earth and gravel made it difficult visually to detect the cable fence itself.
At first instance in the District Court of NSW, Delaney ADCJ accepted Ms Martin’s case, which was found to be supported by the expert evidence of Mr Grieve, a building consultant and civil engineer. Ms Martin’s award of damages included a component for past and future gratuitous domestic assistance provided by her husband, who is in receipt of a full-time carer’s allowance.
The Councils appealed to the NSW Court of Appeal.
Section 79 of the Evidence Act 1995 (NSW) makes admissible evidence of an opinion which is wholly or substantially based on ‘specialised knowledge’ that, in turn, is based on the witness’s training, study or experience.
The Councils submitted that it was not established at trial that Mr Grieve had specialised knowledge by reason of his training, study or experience which permitted him to express an expert opinion about matters of visual perception; or that he was doing so based on that specialised knowledge.
In his evidence, Mr Grieve expressed an opinion about two matters of visual perception. The first was that it would have been difficult for a pedestrian to detect the grey cable against the shaded earth and gravel. The second was 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.
The Court of Appeal considered that matters of visual perception and vision science may be the subject of specialised knowledge. For example, the Councils relied upon the expert reports of two professors (one a professor of experimental psychology with expertise in visual perception and vision science, the other a professor who is a psychologist, human factors engineer and a psycho-pharmacologist). Caution must be exercised because human experience and common sense permit laypersons to also express views based on their own experience and observations as to what someone in the position of Ms Martin was likely to have seen. However, those observations and that knowledge do not, for that reason alone, form part of the body of purely specialised knowledge upon which an expert’s opinion depends and which equips the expert to give such an opinion.
Mr Grieve described himself as a building consultant, civil engineer and lawyer, and his work history included structural designer, construction manager and design engineer roles. His reports did not identify the field of specialised knowledge in which he had expertise by reason of his training, study or experience that is applied and relied on to justify his opinions. Accordingly, the Court of Appeal found the primary judge had erred in admitting Mr Grieve’s evidence.
Risk of injury
The primary judge found that the positioning of the concrete blocks behind the post and cable fence created a risk of injury because pedestrians seeking to negotiate a way through the blocks would have focussed their attention on walking through the gaps between the blocks, paying less attention to the cable.
The Court of Appeal considered that the evidence did not establish the risk of harm caused by the positioning of the concrete blocks and the retention of the cable was ‘not insignificant’ for the purposes of s 5B(1)(b) of the Civil Liability Act 2002 (NSW). The presence and positioning of the concrete blocks was plain and obvious. While the focus of a person approaching the concrete blocks would have initially been directed to the gaps between them, the timber posts and cable in front of the blocks would have been observable too. The spacing of the timber posts did not correspond with that of the concrete blocks, and the timber posts in varying degrees obstructed the gaps between the concrete blocks. The positioning of the posts in turn directed attention to the cable, which was clearly visible against the light background of the concrete blocks. It is clear that someone using reasonable care for their safety could not attempt to pass through a gap between the concrete blocks without also noticing the timber posts and cable.
Accordingly, the risk of someone tripping or falling on the cable was ‘obvious’ within the meaning of section 5F of the Civil Liability Act 2002 (NSW) and was not such that a reasonable person in the Councils’ position would have taken the precaution of removing the cable, notwithstanding that the burden of doing so may not have been onerous and that the social utility of retaining the cable was questionable.
Damages for gratuitous care
The Councils submitted that the primary judge erred in making any allowance for gratuitous domestic care services provided by Ms Martin’s husband as he was receiving payment as a full-time carer at the date of the injury. The Court of Appeal dismissed this submission, finding that it is appropriate to make an allowance for future care representing the escalation in Ms Martin’s care needs following the injury. It may be a different circumstance where a carer’s allowance is awarded by reason of the injuries the subject of the claim alone.
Particular care needs to be taken where an expert opines on matters of visual perception to ensure that the expert has expertise in matters of visual perception and/or vision science by reason of their training, study or experience.
Further information / assistance regarding the issues raised in this article is available from the authors, Alev Byrne, Associate and Ian Denham, Partner, or your usual contact at Moray & Agnew.
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