(NewsNation) — The only surviving child of so-called “Doomsday mom” Lori Vallow, charged with murdering her two youngest children and a romantic rival, confronted his mother in court.

Former homicide prosecutor Matt Murphy and Gigi McKelvey, host of the “Pretty Lies & Alibis” podcast, joined “Elizabeth Vargas Reports” to discuss the latest developments in the trial.

Murphy called Colby Ryan’s testimony “a bombshell.”

“There’s a moment in that. It’s very subtle,” Murphy said. “But Lori Vallow can be heard. Here’s this earnest young man confronting her about the murder of his siblings and the death of his only father he ever knew. And she laughs at him. And I’ll tell you what, that is incredibly damning testimony. And it is very bad for her.”

Ryan is Vallow’s oldest child and took the stand in the bizarre triple murder case in Idaho. 

Prosecutors played audio from a phone call shortly after Ryan took the stand. The call was made after the bodies of Ryan’s siblings, Joshua “JJ” Vallow and Tylee Ryan, were found buried.

McKelvey called the interaction between Vallow and Ryan “awkward.”

“Laurie definitely kept her eyes on Colby,” McKelvey said. “It looked like she was maybe trying to make some kind of a visual connection with him. He wasn’t having it. He looked her way once when it was clear she was turned away and talking to her attorneys. And the last look he gave his mother … was a look of pure disgust. He stared at her for about four or five seconds as he walked out and didn’t look back.”

The call continued for several minutes, with Vallow Daybell insisting that Ryan can’t know what happened because he wasn’t there.

Ryan said his mother lied to him multiple times while his brother and sister were missing.

“She did get emotional a few times, wiped her eyes. I couldn’t see tears from where I was. But I had other people who said they did see tears,” McKelvey said. “It was pretty clear Colby is angry. He’s devastated and I think she got the message for sure.”

The Associated Press contributed to this report.