11:25am
Dr Andreas Marnerides said pneumonia was likely to be present at birth for Child D.
Professor Arthurs talked of a 'black line' in front of the spine indicating gas in the great vessels, which was "unusual" in children who had died without an explanation.
It was present in "two other children", one of whom was Child A.
There was "more air" in Child D than Child A.
One explanation was someone was injecting air into the child, and the radiograph images were consistent with, but not diagnostic of, externally administered air to Child D.
Dr Marnerides said the presence of air in such a vessel was "significant".
He said from a pathology point of view, air embolus could not be proved.
He said there was "no other natural disease" that could explain Child D's death.
He said in his opinion, Child D died with, not from, pneumonia.
He concluded the 'likely explanation' was air embolus.
Dr Dewi Evans said the 1.30am episode was "very surprising and unusual" as Child D had been responding to treatment and was "a stable baby".
He said Child D had symptoms of early onset pneumonia and had developed that before birth, but was making a recovery.
He said he could not think of any events which would end with unsuccessful resuscitation, and the cause was an air embolus.
Dr Bohin peer-reviewed Dr Evans' reports and conclusions.
She said the striking feature of all events was they were sudden and unexpected, and came with mottling of the skin.
She said it was a concern that Child D was crying in the second event.
She said although antibiotics were given late, there was nothing, clinically, to suggest Child D was going to collapse.
"This was not a picture of a baby with pneumonia severe enough" to collapse.
She was "clear" infection did not cause the "sudden" collapse.
There were episodes of discolouration which was consistent with the limited recorded events of air embolus.
She concluded air had been administered intravenously, causing an air embolus