If my memory serves me correctly, KB had admitted to her mother that the gun incident happened. Like you, I think he played head games and probably said very hurtful things to her, possibly ridiculed her. If you look at her Pinterest page you will see many quotes about relationships that make you think that she was in one that was painful and that she was conflicted as to whether to stay or leave. The quotes will show a date that the original posted uploaded the quote, but not when KB posted the quote, so it doesn't help with timelines; however, I felt like reading some of those that PF was putting her through stuff. He did use the incident to portray himself as a caring hero. Reminds me of another incident of duplicity...when he told KB's mom that he loved her daughter after he had savagely beat her to death and burned her body.
I feel like when this goes to trial, friends, coworkers, and her church members will probably come forward with more information about what PF put her through. Although she is quiet, people like her are usually very truthful and candid with a very few people that they trust. She would almost surely had to confide in someone.