A well-known figure in the LA court system, Katz was appointed as the child custody evaluator for the case at the beginning of October. His role is to interview the parents and children individually and then interview the children with the parents.
He also talks to grandparents, school teachers and doctors.
“Angelina was annoyed when the judge ruled that he wanted an independent evaluator to speak to the kids and give his recommendations on who should have custody,” says the source.
“She never thought for a moment that they’d all say they wanted to be with Brad. This has been a massive kick in the stomach for her.”
Significantly, all the children have confirmed in interviews that Brad is a fun and relaxed parent and only ever says nice things about Angelina to them.
“Even though he’s just as angry over the split as she is, Brad’s made it his mission to never speak poorly of Angelina in front of the kids and has worked hard to make home a calm and happy place for his family,” adds the insider.
“This really came out in the interviews and was a big factor with the evaluator.”
And Brad’s tactic is working, with the insider revealing Ange has been made to look like the bad guy during the court proceedings.
“He’s coming out of it smelling like roses, where as Ange looks like she’s going to lose the kids – for good.”
In public, the pair have become increasingly combative since their 2016 break-up. In August, Angelina’s attorneys accused Brad, 54, of not paying any “meaningful child support” while his camp hit back quickly, accusing her of attempting to “manipulate media coverage”.
The judge also warned Angelina to stop limiting the children’s access to Brad and warned that she risked losing custody unless she made moves\ to improve the kids’ relationship with their dad.
Until now, however, Angelina has been convinced her six children – Maddox, 17, Pax, 14, Zahara, 13, Shiloh, 12 and twins Knox and Vivienne, 10 – want to live with her and she has been pushing hard for full custody.
“This has completely blindsided Ange, and she’s been left pretty shell-shocked to say the least. She was convinced that the kids wanted to be with her, so this has come as a total shock,” says the insider.
The news comes as Brad’s family publicly slammed Ange, 43, for “completely destroying” Brad’s life.
Lori Duggan-Heisler, a former confidant of the actor and a close Pitt family friend, told the National Enquirer that Brad was pressurised into marrying.
“I think he only married Ange because it’s what their children wanted. He probably knew in his heart that he married her for the wrong reasons,” she claims.
Last week it was also claimed Angelina is planning a permanent move to France in a bid to thwart Brad’s efforts to get joint custody.