Great thread. I wanted to add another element I didn't see in your invalidating post: gaslighting.
For those that don't know, the term comes from a late 1930s play that was made into several movies (the best known was the '44 film starring Ingrid Bergman). In it the husband slowly over time psychologically manipulates his wife into believing she is going insane in order to control her. He does this by denying what she experiences or does things and then accuses her of doing them.
So, one of the ways to invalidate is to deny the memory of the woman (it is almost always a done by men to women, but it doesn't have to be). Over time, this destroys the woman's confidence in her own ability to trust herself and her sense of reality. The perpetrators are usually classified as sociopaths (they use lies without remorse to get what they want).
Things will start very small. Little denials that really don't seem like a big deal worth really making a huge fuss over. They often rely on the gender socialization of both men and women to defer to male confident assertion and female hesitance to assert herself. By the time they build into really manipulating behaviors to maintain control the victim has really come to doubt herself and her senses. It is pernicious because the woman comes to blame herself and think it is something wrong with her, and therefore has trouble detecting the problematic consequences of the manipulation (she focuses on the perceived error on her part rather than what it allows the man to get away with).
Now, all that said, there are legitimate reasons for couples who are having R problems to argue about what exactly happened. One of the main reasons is that memory is selective, and if there is building R anxiety the hippocampus (part of the brain that plays a huge role in memory) actually shrinks and other parts of the brain that further disrupt the function of the hippocampus start kicking in faster and stronger. A sign that this is the problem is to discuss this with your partner and the important R rule: it is better be loving than right. During any argument, you can call for a time out and remind your partner of this problem. They should move to restore the emotional breech, and over time the couple should get better at doing this.
The sociopath would either try to keep manipulating or give up on this path and switch to another tactic in all likelihood. So, I'd look for an escalation (pushes this further to get you back under control and continue gaslighting) or a really sudden cessation of such behavior. The reason for the later is that they know exactly what they are doing. It is strategic. They are good at being strategic, and in switching tactics to match the situation. In the couples where there is a genuine problem with conflicting memories, especially due to R stress, aren't conscious of the behavior and will not be able to just turn the behavior off. So sometimes the strategic skill of the sociopathic abuser helps unmask them, as most of us are much too bumbling and stuck in our ways to be able to control ourselves quickly.
Not foolproof, but hopefully that is helpful.
Me: 50 W:43 S6, S3 M: 12 yrs. T: 17 M is bad & Not happy Bomb Mar '14 S 5 Feb '15 D Bomb 13 Apr '15 (but "no hurry") DB Coach May '15 Wants proceed on D Aug '15 Starting 1-on-1 negotiations Sept '15