Rafting trip

The x and his fiancee took my middle son on a rafting trip recently. According to my son, the x got mad at the way the fiancee and he were rowing the boat.

He yelled at him and the fiancee making the fiancee scared and mad. My son told her just to accept it...take it and he'll stop eventually.

Time will tell how long she takes it. What kind of person does that make me if I could've stopped this behavior from continuing on to the next person? What if he kills her? Does that make it partly my fault? Do I have a moral obligation of some sort? Do I just pray for her?

Sad state that my son's reaction is acceptance. I taught him well, huh? So sad that I did.