No Recollection
“You’re so thoughtless. Do you remember when…” “You never back me up. Remember how…” “Why don’t you ever come to my defense? This is just like that time you…” These would be legitimate reasons to be angry at your SO if they were true. However, the OP had no idea what this woman was referencing.
It was like she was coming up with arguments in the shower and blaming her boyfriend for not sticking up for her. In those arguments. That never really took place. That she was using as ammunition to attack him. We think she just wanted to find a way out of the relationship without looking like the bad guy. Well, mission failed.