OTTAWA -- Questions were raised about steering, speed, and whether the bus driver was distracted at any time on the final day of testimony at the Westboro bus crash trial.

On Monday, Crown attorney Dallas Mack showed the defence's key witness, collision reconstruction expert Richard Lamoureux, video of Aissatou Diallo on the day of the crash using her phone then putting it away before picking up passengers. He then went through grainy video that he alleged showed Diallo taking a headphone out of her ear after the crash and the phone in her hand as she rushes to the top floor of the bus.

Diallo's defence team said there was "no evidence of her using the phone while on the bus."

Fady Mansour asking Lamoureux "was there anything in any of the reports or any their drafts that considered the issue of distracted driving or Ms. Diallo using or being on her phone or manipulating her phone?"

"There was nothing," he said.

The Crown contends Diallo never braked or steered the bus away—even briefly hitting the gas.

"We agree that the bus is moving towards the right and seemingly a straight line," Lamoureux testified.

"If it's moving to the right sir, then I'm going to suggest there is no input of left steering, you don't disagree with that, do you?" Mack countered.

"I don't disagree," Lamoureux replied.

Lamoureux previously testified the bus struck two snowbanks and a rockface before the shelter leaving Diallo little time to react.

"Sir I think the operator panicked. We see the throttle blip application, the signal application, I think at that point the operator's just holding on," Lamoureux said.

During re-examination, Lamoureux said "in this case with one wheel being on asphalt, one being in the gutter, we're essentially cutting down half of the turning force available to this bus to change its direction."

The defence argued sun glare, confusing road markings left over from previous construction along with other factors were at play.  

Bruce Thomlinson, Judy Booth and Anja van Beek were killed in the crash. Dozens more were injured.

Diallo has pleaded not guilty to 38 charges of dangerous driving, including three counts of dangerous driving causing death.

The judge will hear closing arguments in the coming days.