
July-August   41
...UNTO  
ITSELF
LAW
I
n a recent case, a student from a 
Taiwanese background brought 
proceedings to challenge the Leaving 
Certificate course in Mandarin 
Chinese. The issue was that the school 
course taught the ‘simplified’ characters 
used predominantly in China, rather than the 
‘traditional’ characters, used mainly in 
Taiwan. The marking scheme for the Leaving 
Certificate was weighted towards students 
who used the simplified characters.
An  expert witness for the applicant 
claimed that the weighting towards 
simplified characters was “discriminatory 
and exclusionary”. Another expert said it 
was “unfair, discriminative [sic] and 
counterproductive” for the Department to 
“refuse” to correct answers in the traditional 
characters. 
However,  as pointed out by Mr Justice 
Garrett Simons, the question of whether the 
weighting was discriminatory was not a 
matter for an expert witness. This is a matter 
that the judge should be in a position to 
determine once he or she understands the 
issues. In this case, the issues requiring 
expert assistance were: (a) the practical 
distinction between simplified characters 
and traditional characters; and (b) the 
logistics of teaching Mandarin Chinese by 
reference to the two script systems. The 
question of what system was to be used had 
been a decision for the Minister for 
Education, and the court could only interfere 
if the decision was made in an unlawful or 
irrational manner. As the Leaving Certificate 
Mandarin Chinese course was aimed at 
pupils who were not native speakers of the 
language, it did not unfairly discriminate 
against a student from a background that 
used a dierent script. 
The  relationship between courts and 
expert witnesses has long been problematic. 
There are issues in large numbers of cases 
that cannot be determined without the 
assistance of an expert. Engineering experts 
are needed to explain road trac accidents 
and accidents in the workplace. Accountants 
and actuaries are needed to explain complex 
financial matters. Pathologists and other 
medical practitioners are needed in 
homicide and rape cases.
It does not take much reflection to realise 
that a judge or jury considering such a case 
requires the expert witnesses to be objective 
and unbiased. If experts only consider the 
facts that suit their own client’s case, or 
present their specialist knowledge in 
relation to one theory rather than another, 
the court does not properly have the benefit 
of their expertise. 
A litany of familiar miscarriages of criminal 
justice have had faulty expert evidence at 
their hearts: the Dreyfus aair (handwriting 
experts); the Birmingham Six and Judith 
Ward cases (chemistry); the Guildford Four 
(forensic testing of nitroglycerine); Sally 
Clark (paediatrics and pathology); Amanda 
Knox (DNA); and Barry George (ballistics). In 
the recent Post Oce prosecutions in the UK 
concerning the Horizon computer network, 
it has transpired that there was systematic 
misconduct among lawyers and computer 
experts that gave rise to several hundred 
wrongful convictions.
If the experts in any of these cases had 
acted independently, presenting the science 
in an objective manner, it is likely that the 
wrongful convictions would not have 
occurred. Even where there was also 
misconduct by police investigators or 
prosecution lawyers, they generally relied 
on the scientific evidence to secure the 
convictions. 
It can be dicult for experts to understand 
their duty of independence and objectivity if 
it is not explained to them in clear language 
by their instructing legal team. The Irish 
courts have long bemoaned the practice of 
experts whose evidence “all too often 
appeared to correspond too favourably with 
the interests of the parties who retained 
them” (comments by Ms Justice Mary Irvine 
in the 2017 case of Byrne v Ardenheath).
Keeping your 
witnesses about you
Expert winesses nd heir duy o 
he jusice sysem
By Mrk Toenhm