This could be used as a teachable moment, yeah. I had been thinking that as a kid i would have been really distressed if a family elder acted that way but part of the reason I would have been distressed would have been that I would have been reasonably terrified my parents would blame me. Other people have an opportunity to do better!

I do think that is a churlish way to treat kids, though. No matter what bullshit their parents or grandparents may have pulled.