Marie Henein's cross-examination of the first complainant in Jian Ghomeshi's sexual assault trial covered the most minute details of the woman's testimony — but she didn't ask about the allegations the witness was "violently punched" at the former broadcaster's home.

That omission strongly signals the former CBC Radio host will not testify, Toronto lawyer Daniel Lerner says.

A former Crown attorney turned defence lawyer in 2014, Lerner says the legal rule of Browne v. Dunn would force Henein to ask the witness about the alleged punching if she planned to present contradictory evidence.

"Ms. Henein, being one of the most experienced criminal lawyers in our bar, she knows that," Lerner says. "They're probably not presenting an alternative version ... Instead, it seems the defence strategy is to show that the evidence being called by the Crown is of such low reliability — or credibility — that there's not enough to prove this happened beyond a reasonable doubt."

Ghomeshi, 48, who lives in Toronto, is charged with four counts of sexual assault and one count of overcoming resistance by choking involving three women. The incidents are alleged to have occurred in 2002 and 2003.

Ghomeshi is not legally required to testify at the trial.

In a sexual assault trial, there can often be limited physical evidence. The verdict then comes down to determining if the narrative is believable, Lerner says.

Jian Ghomeshi Trial

Marie Henein, left, spent considerable time eroding the first witness's credibility on Monday and Tuesday at the Ontario Court of Justice. (Frank Gunn/Canadian Press)

Henein used her cross-examination, which started Monday on the first day of the trial, to highlight inconsistencies between one of the complainants' sworn testimony and earlier statements she gave to police and media outlets. While Lerner says the court understands small details may change in a complainant's memory over time, the lawyer said the defence seriously eroded the witness's reliability by presenting two emails she had sent to Ghomeshi more than a year after the alleged assaults. In the second one, she also included a photo of herself wearing a bikini.

This was revealed a day after the witness told the court she had no contact with Ghomeshi following their dates in 2003, except for "maybe" drafting an email "in anger" which she told the court she was unsure she sent.

"It was a blistering cross-examination but one that [Henein] did effectively, demonstrating the problems with relying on this witness's evidence — and did so without any type of exaggeration," Lerner says. "She just let the witness herself dig her hole."

Vulnerable in cross-examination

Given Henein's approach so far, Ghomeshi has little to gain by testifying, Lerner says.

Testifying would also leave him vulnerable to a cross-examination by the Crown.

Lawyer Jonathan Rosenthal, however, says that it's still too early in the trial to speculate about whether Ghomeshi will remain silent. Henein's decision on whether to put Ghomeshi in the witness box could still depend on the testimony of the two remaining complainants, the 27-year veteran of criminal litigation says.

"But if this were the only witness against him in the case, no lawyer worth their salt would be calling the defence," Rosenthal says. "If this were it, the case would be over."

Ghomeshi Trial

In this artist's sketch, from left, Jian Ghomeshi, lawyer's assistant Danielle Robitaille, defence lawyer Marie Henein, Justice William Horkins and a witness appear in a Toronto court on Tuesday. (Alexandra Newbould/Canadian Press)

Both Rosenthal and Lerner agree that Crown prosecutor Michael Callaghan would likely have had no knowledge about the two emails between the witness and the accused. When CBC asked the complainant's lawyer whether she had disclosed that information to the prosecution, he refused comment.

Potential bombshells

It's the police that collect evidence around which to build a case, not the Crown.

And Rosenthal said there's "absolutely" no way that investigating officers would ask about emails that are a dozen years old.

Lerner said the prosecution would likely have tried to defuse any potential bombshells by having the complainant frame the evidence herself while being questioned by the Crown.

"In a big case you like this, you don't want surprises," the former prosecutor says. "Strategically, you want to address that head on so that it reduces the impact."