If you haven't dealt with someone with NPD or BPD, I'd like to clarify this a bit. I'm sure that any of the prolific commenters on HN could be found to have contradicted themselves and/or distorted reality occasionally. This is about patterns of behavior, and it's usually coupled with minimizing any specific examples of the behavior while never engaging with the fact that the problem is the pattern of behavior, not any one example.
I've dealt with someone with eBPD who was unable to get through a 45 minute therapy session without contradicting themselves. They also habitually selectively report facts to distort reality[1]. If the estranged kid(s) really were the ones with personality disorders, I suspect the emotional responses to being cut out would be something along the lines of "Sad, relieved, guilty about feeling relieved."
1: Here's an example with details changed: "Joe drank too much last night and we got in a car crash." Reality, Joe was in the passenger seat, and the driver hit a deer that jumped out in front of them. On confrontation: "I never said Joe drove drunk!"