Expert Witness Journal Issue 68 August 2026 - Flipbook - Page 82
chose to examine. That institutional con昀椀dence is
understandable. It is also exactly the dynamic that
the law, as currently interpreted, tends to reward.
The senior coroner declined to hear oral evidence
from the management of Transport for London or
Tram Operations Limited. Her reasoning rested
squarely on the line of authority that began with
the Norfolk helicopter case: because there was, in
her judgment, no credible evidence that the RAIB
investigation was incomplete, 昀氀awed or de昀椀cient,
she considered herself “not permitted to call further
evidence.” The jury returned a conclusion of
accidental death. The families called it a farce and
said justice had been su昀昀ocated. We understood
why. People who were, on any view, well placed to
speak to the systemic causes of seven deaths never
entered the witness box.
The coroner’s hands, largely tied
The courts have built a high wall around accidentbranch conclusions. The governing principle,
drawn from R. (Secretary of State for Transport)
v HM Senior Coroner for Norfolk [2016] EWHC
2279 (Admin), through HM Senior Coroner for
West Sussex v Chief Constable of Sussex [2022]
EWHC 215 (QB), and consolidated in R. (Mid and
West Wales Fire and Rescue Service) v HM Assistant
Coroner for Carmarthenshire and Pembrokeshire
[2023] EWHC 1669 (Admin), is straightforward
to state and formidable in e昀昀ect. Where one of
the statutory accident investigation branches has
investigated, a coroner should treat its 昀椀ndings as
the evidence as to the cause of the accident, and
should not re-investigate the same ground, unless
there is “credible evidence” that the investigation
was “incomplete, 昀氀awed or de昀椀cient.”
That experience is the reason we write. The disquiet
it left is not about any single coroner’s exercise of
discretion. It is about a structure that, taken to its
logical end, can leave the most important questions
about how people died beyond the reach of the only
public, judicial inquiry many families will ever get.
A closed shop investigating itself
The threshold is, in the courts’ own words, a “high
hurdle.” It is expressly “all or nothing”: either the
investigation can be relied upon in full, or it cannot
be relied upon at all, and there is to be no cherrypicking between conclusions. Minor criticisms do
not su昀케ce. Nor does the wisdom of hindsight, the
observation that conclusions could have been better
expressed, or even the identi昀椀cation of a discrete
error, because an inspector “does not have to be and
cannot be infallible,” and a sound investigation can
still produce an incorrect conclusion. The rationale
is the public interest in avoiding duplication and
respect for specialist expertise. A coroner, the West
Sussex court said, should be “very slow” to 昀椀nd that
an expert investigation was incomplete, 昀氀awed or
de昀椀cient.
The RAIB is, in form, an independent statutory body.
Under section 7 of the Railways and Transport Safety
Act 2003 it must investigate serious railway accidents
and must try to determine what caused them but,
critically, it “shall not consider or determine blame
or liability.” Its purpose is the improvement of safety,
not the apportionment of fault. That is a perfectly
sensible design principle. No-blame investigation
encourages candour; witnesses speak more freely if
they are not building a case against themselves.
But the design has a less comfortable feature
that is rarely examined in the courtroom. The
expertise that makes the RAIB authoritative is
drawn overwhelmingly from within the industry it
investigates. Its inspectors are, in many cases, former
railway engineers, operators and managers, people
who have spent careers inside the very organisations
and the very culture under scrutiny. That is precisely
what equips them to read the marks on a sleeper or
reconstruct a sequence of events from damaged
infrastructure. It is also precisely what should make
us cautious about treating their conclusions as
beyond challenge. An investigation conducted by
insiders, however technically excellent, carries an
inherent risk of shared assumptions, professional
sympathies, and blind spots about systemic and
managerial failings that an outsider might press
harder. There is nothing improper in any of this. It
is simply the nature of a specialist body that recruits
from a single industry. The “closed shop” is a feature,
not a scandal, but features have consequences, and
one consequence is that the body marking the
homework was trained in the same school.
We do not quarrel with the principle that resources
should not be squandered on duplicative inquiries.
But the practical e昀昀ect, as Sandilands illustrates, is
that the gateway to a fuller inquest is guarded by a
test that is exceptionally di昀케cult to satisfy before
the very evidence that might prove the investigation
de昀椀cient has been heard. There is a circularity here
that ought to trouble us: the families could not show
the investigation was de昀椀cient without exploring
the systemic failings, and they were not permitted to
explore the systemic failings because they had not
昀椀rst shown the investigation was de昀椀cient.
Challenge it anyway
None of this means the door is bolted. It means
counsel must approach it with strategy and
persistence rather than resignation.
Our experience is that the RAIB defends its reports
昀椀ercely at inquests and can be notably cloth-eared
to criticism of its methods or the scope of what it
EXPERT WITNESS JOURNAL
First, the “high hurdle” is a hurdle, not a prohibition.
The authorities expressly contemplate that an error
may, on proper analysis, reveal that an investigation
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AUGUST 2026
