You know how when a child dies, it’s common for the parents to blame themselves? Even if it wasn’t their fault? And that the relationships usually deteriorate because each parent then starts to lash out at the other with blame in order to try to avoid their own guilt relating to the death?
Well, I think that if the argument runs along the lines of “You throw like an idiot!” – “What? Learn to catch you fuck!” then both parents may actually be at fault and they can probably share that blame.