Sometimes the something minor can be the final pebble that causes the avalanche. LW saying the same things one too many times and the son just can't take it anymore. Or. The something minor can be something in the opposite direction. The son just decides that this is the hill he wants to die on and refuses to speak anymore. Either way. The person has stopped talking and the LW needs to get some help to stop obsessing over it. Let it go. It isn't worth it to obsess. Even with all this time the pandemic has created to navel gaze, let it go.