If this (Tony) had been the only time Cindy resorted to this behavior I wouldn't take issue with it because of the extreme provocation and stress she was under at the time. But this wasn't the only incident; we already know of several other times she's indulged in this same nasty retaliatory behavior.
In addition to Ryan, Amy, and Tony, there was her contemptuous remark to Jesse when KC was around 18. To paraphrase that one: "Why would you want to marry somebody like her with no future..." IMO, this one is completely inexcuseable and probably unforgiveable in KC's eyes. Jesse must have felt the same way, because he's still thinking and talking about it.
There's no point in our debating this subject because we each have our own standards and restrictions for good parenting. My own included, "Never criticize or belittle your child (or adult child) to or in front of his/her friends. Never."
But that's just me and, hey, I'm no saint. I don't have nearly as much restraint as Cindy did when KC got out on bond and came home. The first night, I'd have hugged her warmly, and sat down to talk quietly to her--until she started feeding me nonsense about a non-existent nanny and tried convincing me that she could only give me "hints" and riddles about what happened. At that point, I would have asked LP and everyone else to leave the house for an hour so that Casey and I could "argue in private."
And then I would have urged her into the bathroom for our "extra privacy"---grabbed her by the hair, and dunked her head in the toilet bowl until I either had full answers to my every question, or else she'd swallowed all the water in the toilet bowl. Or drowned in it.
I kid you not. I really fear that in Cindy's place, I'd have lost it entirely with KC.