TORONTO - The Crown is conceding that it was a "miscarriage of justice" when a man pleaded guilty in the death of his two-month-old son because of the daunting spectre of testimony from now-disgraced former Sick Kids' pathologist Charles Smith.

Both the Crown and the defence are calling for the Court of Appeal for Ontario to acquit Richard Brant, in light of fresh evidence. The court is scheduled to hear his case Wednesday.

Brant, now 38, was charged in 1993 with manslaughter in his baby's death the previous year. He eventually pleaded guilty to aggravated assault.

Brant was taking Dustin for a walk after the boy had been sick for a few days. When he lifted the rain guard on the stroller he was horrified to find Dustin's lifeless body with thick, red foam around his nose, Brant says in an affidavit.

The infant was taken to hospital and died two days later.

While the pathologist who conducted the autopsy listed pneumonia and respiratory failure as causes of death, Smith examined the case and concluded Dustin likely died from Shaken Baby Syndrome.

He maintained he never did anything to intentionally cause Dustin's death, but his lawyer Robert Graydon, now an Ontario Court judge, told him Smith was the "God" of his profession.

With his word against Smith's word, facing a lengthy prison term if convicted, and having just found out his girlfriend was pregnant, Brant pleaded guilty in 1995 to the lesser charge and was sentenced to six months, Brant's lawyer writes in documents filed with the court.

"If I knew then what I know now, I would not have done so," Brant says of his guilty plea in an affidavit. "I ask the court to take the burden of having harmed him from my shoulders."

Once considered an unassailable expert on child forensic pathology, an inquiry found that errors in Smith's work were responsible, in part, for several people being wrongfully convicted and sent to prison for killing children.

In addition to the inquiry coming down hard on Smith, other reports and reviews have noted his errors and his findings have been lambasted numerous times in court in recent years.

His medical licence was revoked earlier this year.

The Crown and defence had experts examine the evidence, and while none of them can eliminate shaking as a possible cause of death, all independently put forward an alternative cause or causes of death, Brant's lawyer James Lockyer writes in court documents.

"The evidence establishes that Dustin likely died of natural causes while in the case of (Brant)," he writes.

The Crown agrees with Lockyer's call for an acquittal, saying in documents filed with the court that with changes in science and forensic pathology, the evidence now can't support a conclusion beyond a reasonable doubt that Brant harmed Dustin.

"Fresh evidence establishes that the plea should be set aside as a miscarriage of justice," writes Crown lawyer Alison Wheeler. "The appellant has explained his guilty plea, and there is compelling fresh evidence which now shows that no reasonable jury could convict the appellant of the alleged offence."