What a great story! And rather than be sad that your kids are "still" learning this, be glad that they ARE. And they are learning important lessons that how you treat others--especially family--MATTERS. They might not have seen it so clearly without the contrast. (Not suggesting this makes their dad's abusive behavior any less bad--just noting that some lessons are underscored when you really see the results of both alternatives.)
So glad kiddo is OK and that he's taking this the right way. I've always felt everyone should have a major car accident, not involving injury, to learn how easy it is to lose control of a vehicle and how bad it could have been.