Q&A Is His Inability to Recall Details of the Affair Normal?

I walked in on my husband and his affair partner. I am not sure I will ever get those images out of my head. My husband has since disclosed a 2 year emotional & physical affair. We are doing Bootcamp & are registered for an EMS Weekend. My husband is starting counseling. He has been doing a lot of reading and diagnosed himself as a sex addict. One challenge I am having is that I do not believe I have full disclosure, partly because there are many questions my husband says he cannot recall. He keeps saying he has nothing to gain by withholding information at this point. I am sure this is painful for him as well, but it is hard for me to understand and move forward feeling like I don’t have the answers to help me fully understand. It is probably important to note that through discovery of affair #2, I realized that there was not full disclosure of #1, when it happened. This just reinforces my lack of confidence in disclosure. Sometimes I think I will never have all the answered or fully understand, so I should let it go. However, I feel I deserve answers. Is this inability to recall normal? What is your experience in this area?