BARRIE, Ont. -- A young Ontario father accused of critically injuring his infant daughter and leaving her with severe brain damage has been acquitted after a court found it could not rule out the possibility that the girl had been harmed by her mother.

The man, then 19, was charged with aggravated assault and failing to provide necessaries of life after his then one-month-old baby was taken to hospital on December 27, 2016.

Court documents say the girl continues to show “significant developmental delays and a limited prognosis for recovery.”

A medical expert testified at trial that the child had been hit on the head or shaken, or both, but could not pinpoint at what time she was injured, only that her symptoms would have emerged within minutes and worsened with time.

In a decision released last week, Ontario Superior Court Justice Joseph Di Luca says the injuries were inflicted by one of the girl's parents, but based on the evidence, it is not possible to say which one.

A Barrie, Ont., court heard the baby's father took care of her at his family's home on Boxing Day and brought the child to her mother around noon the following day.

At the time, the girl appeared pale and fussy and had refused to feed, but court heard these symptoms were “non-specific” and could be present in a child that does not have a brain injury.

The mother tried to take the baby to a previously booked doctor's appointment but realized she had gotten the date wrong and the doctor's office was closed, the document says. Frustrated, she decided to go shopping with a friend later that afternoon, taking the baby with her, it says.

The friend noticed the baby twitching violently sometime after 4:30 p.m. and grew concerned, suggesting the child be taken to hospital, court heard. The child's mother continued to shop for about 45 minutes and called Telehealth around 7:45 p.m.

Ambulances then whisked the baby to hospital, where doctors found she was lethargic, had an irregular heartbeat and at times stopped breathing, court heard. She was also twitching on her left side and required “extensive life resuscitation efforts,” the document says.

She was transferred to Toronto's Sick Kids hospital and diagnosed with extensive retinal hemorrhages in both eyes and bleeding on both sides of the brain, it says. She also had swelling and a tear to the brain tissue, bleeding around the spine and damage to the ligaments around the base of her skull, neck and spine, it says.

“This is an incredibly tragic case. A young baby, barely a month old, sustained severe brain injuries that imperilled her life. By some miracle, she did not die. Her life was, however, forever altered,” Di Luca wrote in his judgment.

“On the evidence before me, it is likely that both (the mother and father) were too young and too ill-equipped to become parents.”

The Crown's case against the father was “entirely circumstantial,” with no direct evidence that he harmed the baby, the judge wrote. In order to convict him, his guilt must be the only reasonable conclusion available based on all the evidence, Di Luca said.

Prosecutors argued the mother's testimony, in which she denied hurting her baby, combined with the circumstantial evidence made the father's guilt the only reasonable inference, the document says.

The defence, meanwhile, challenged the mother's credibility and said there was at least a reasonable doubt based on the timing of the baby's injuries.

The judge said it was possible the baby was injured when she was brought to her mother, but he said it was also possible the girl “simply was tired from having been moved around a lot at Christmas, was not eating that morning because of changes in her diet and was pale and cold due to the weather.”

The baby's condition worsened with time, he said.

“While it is possible that the child was manifesting symptoms of the injury that grew more severe as the day progressed, one other possible explanation is that the child was injured later that day,” he said.

Di Luca agreed there were issues with the mother's credibility, noting she lied to police about going out with friends on Boxing Day, and her evidence about the father had “an element of hindsight bias and animus.”

What's more, he said the woman's account of the shopping trip was “concerning,” suggesting she perhaps did not want to admit that she kept shopping after her friend told her to take the baby to the hospital or that she was not being candid about what happened to the child.

“She is clearly reluctant to seek medical attention when it is obvious that the baby is in distress,” the ruling reads. “This reluctance raises a concern that she possibly had something to do with the child's injuries and was, perhaps, hoping that the child was going to be OK without the need for any medical intervention.”

While the judge did not accept her denial of responsibility, he stressed he was not making a finding that she had harmed the child. Nor could he conclusively find that the father had done so, or that the young man had failed to get the baby the medical attention she needed.