A scenario put forward by a man accused of murdering a baby was "entirely possible" as an explanation for the fatal injuries, a jury has been told.
Specialist forensic pathologist Professor Johan Duflou gave evidence for the defence on Thursday at the Newcastle Supreme Court trial of Jie William Smith.
The 31 year old has pleaded not guilty to murdering his then partner's six-month-old son who went into cardiac arrest early on February 9, 2019 in New Lambton.
The Crown has rejected the Newcastle man's guilty plea to manslaughter made on the basis that he failed to seek medical attention, knowing the mother had seriously injured the baby.
His barrister Paul Rosser QC asked Prof Duflou to assume the accuracy of Smith's version of what happened, which began with the mother picking up the crying baby around 2am.
The woman, who denied the allegations in her evidence, was then said to have punched the baby in the face and chest twice with the side of her hand, before vigorously shaking him four or five times.
The baby was then said to be bleeding, have had dim eyes, fractious and unsettled, refusing to eat and would just take a sip or two from the bottle.
Mr Rosser then asked the witness to assume that at about 4.15am, his client was holding the child and a bottle, when the baby suddenly went backwards out of his arms and landed on the floor.
Asked how this version fitted in with the presentation of the child's condition when taken to hospital, Prof Duflou replied "yes, it is entirely possible".
He said an earlier shaking and punching of the child could have led to a deterioration in brain functioning and a condition that included seizures which could be a reason why the baby fell out of the man's arms.
Under cross-examination from the prosecutor Neil Adams SC, Prof Duflou agreed all of the baby's injuries could have been caused at the same time.
Justice Helen Wilson asked if he accepted the version about the 2am incident, could he say what the outcome would have been if the child was then immediately taken to hospital.
"It is difficult to say," he replied.
"Potentially the child may still have died, although I could not say with any degree of certainty.
"The longer you wait the more dangerous these abnormalities become."
The trial continues.
