IIRC, Audrey B wasn't part of the casting group. Those were all women from Arizona plus Sarena, who moved to Arizona later. AB lived in another state. She knew Chad from PAP and was friends with another PAP speaker and his wife. According to him, AB spoke to Chad on a weekly basis. It's likely tha she could tell a lot about his teachings (but ZP already did). According to Chad, AB was Jesus' wife in a past life.
As far as AB's testimony at Lori's trial, Lori Hellis was in the courtroom on that day and saw her sobbing uncontrollably while leaving. She might well have been telling the thruh, which JP would spin to portray Lori as bloodthirsty and Chad an innocent lamb.
When it comes to Garth, most people who know him believe that he would tell the truth in court. Leaving things out technically isn't lying.