Expert Witness Journal Issue 68 August 2026 - Flipbook - Page 46
The relevant remedial works were modest. Mr Watts
described raising the balustrade as achievable
at minimal cost. The Court of Appeal endorsed
that description when considered against the
catastrophic potential consequences of a fall.
The di昀케culty was that the factual premise of the
question had not been accepted by the judge. The
judge found no great force, no lifting of the claimant
and no concerted attempt by Graham to propel him
over the balustrade.
The balancing exercise was therefore stark. The
foreseeable consequences were death or catastrophic
injury. The cost and di昀케culty of the precaution
were modest. The exposed population included
young soldiers whose drinking and horseplay
were foreseeable. The existing balustrade was
materially lower than the height accepted in modern
professional guidance.
On the facts actually found, Mr Watts’ evidence
remained that a man of the claimant’s height falling
against a 900 mm balustrade faced a relatively
high possibility of toppling over it, whereas he was
unlikely to topple over a 1100 mm balustrade. The
judge was entitled to accept that evidence and to
conclude that the fall would probably have been
avoided had the balustrade been raised.
Hindsight and inadequate risk assessment
Expert concessions are only as useful as their
underlying factual assumptions. A concession based
upon an extreme or rejected version of events does
not displace the expert’s opinion on the factual
mechanism which the court accepts.
The Court’s treatment of hindsight is particularly
valuable.
It was true that nobody had identi昀椀ed the balustrade
as dangerous before the accident. That was not
determinative. The correct question was not whether
the Ministry did recognise the danger, but whether
it should have recognised it.
In stair and balustrade cases, the expert evidence
should therefore be mapped against each realistic
factual scenario. The expert should be asked:
Previous risk assessments had failed to identify the
danger. That did not establish that the balustrade
was safe. It supported the trial judge’s conclusion
that those assessments had been inadequate.
Repeated inadequate inspections do not convert an
unsafe feature into a safe one.
The duty was anticipatory and continuing. An
occupier or employer cannot necessarily wait for a
near miss or serious accident before undertaking a
su昀케ciently robust assessment. The purpose of risk
assessment is to identify foreseeable risks before
injury occurs.
1.
What is the probable mechanism of the fall on
each available account?
2.
What part did the height, geometry and position
of the guarding play?
3.
What would probably have occurred had the
guarding been at a reasonably safe height?
4.
Does the answer change according to whether
the claimant stumbled, was lightly displaced, was
pushed with moderate force, or was subjected to
a deliberate and forceful propulsion?
5.
Which conclusions can be expressed on the
balance of probabilities, and which amount only
to a reduction in risk?
This is especially important in stair and balustrade
claims. A low guarding feature may remain in place
for many years without an accident. That history
may be relevant, but it is not conclusive. The correct
inquiry remains whether the risk was reasonably
foreseeable, whether the possible consequences were
serious, and whether proportionate precautions
were available.
The question is not merely whether safer guarding
would have reduced the risk in some general sense.
The claimant must prove that, on the facts found, the
precaution would probably have prevented the accident
or injury.
Causation must be tied to the facts
actually found
The sixth ground was the closest. Stuart-Smith LJ
expressly acknowledged that he had not found it
easy to determine.
Contributory negligence: di昀케cult,
but not proved
The causation appeal illustrates a recurring error in
the treatment of expert evidence.
The Ministry argued that 昀椀ghting or play昀椀ghting
near an open stairwell was objectively reckless.
It submitted that the claimant had voluntarily
returned to the landing, could have walked away
and had failed to take reasonable care for his own
safety. It contended for a reduction of 75 per cent.
The Ministry relied upon a concession made by
the claimant’s engineer, Mr Watts. He accepted in
cross-examination that he could not say whether an
additional 200 mm of balustrade height would have
prevented a fall if one person pushed another with
all the force he could muster in an e昀昀ort to knock
him from his feet.
EXPERT WITNESS JOURNAL
44
AUGUST 2026
