12:54pm
The judge refers to Dr Dewi Evans, and his role in providing background evidence for Child A.
He said: "On the whole, babies don't suddenly collapse".
He said Child A was the fifth case he looked at, and the cause of the collapse was "unusual".
He said as he looked at further cases, he noticed a "pattern", as he received more evidence.
He said Dr Evans' evidence came for criticism by the defence.
He had not been in practice since 2009, and the defence said he had "constructed theories" and "acted as an investigator" and was "biased", " putting himself forward...at the outset".
The judge says the prosecution point to a large number of incidents for review with "no apparent reasons for an event or death".
They point to Dr Evans' long experience in neonatalogy, and provided "clear evidence" in Child F and Child L that identified two babies on the unit were being poisoned.
The prosecution say Dr Evans was not handed other potentially incriminating evidence, such as shift patterns for staff.
Dr Evans said Child A was "stable" and "as well as could be expected" before the collapse.
Repeated attempts to insert a UVC or long line may have caused upset to Child A, but would not have caused the collapse, he said.
The lack of fluids "would not make a material difference".
'Bright pink' skin discolouration would be unusual in a baby's collapse - but skin discolouration is "not diagnostic" of an air embolus alone, Dr Evans said.
He denied he had been "influenced" in reaching his conclusion by a 1989 medical paper.
He said in Child A's case, there had been colour change, sudden and unexpected collapse, air in various parts of the body, and no explanation for death.
He said it was probably an air embolus intravenously.
