Events typically don't cause ongoing conflict. Patterns of attitudes and behaviors do. What appears to be cause, usually is not. Personal relationships with partners, spouses or kids typifies surface versus root cause. We spend hours bludgeoning an issue to death.
Hours go by and nothing has been resolved.
Usually, it's an exercise in futility because the core issues are never put on the table. Frustrated and tired, we give up. Only to walk away, knowing, we'll revisit this one again. It won't go away, the real problem hasn't surfaced. They must also reach agreement that whatever the problem is, it shall not interfere with work, nor impede work interaction with each other, other personnel, or clients.