Agreed. I would then want to understand the overall organizational structure that puts "line managers" in these situations. It is almost always some sort of org

Agreed. I would then want to understand the overall organizational structure that puts "line managers" in these situations. It is almost always some sort of organizational defect or lack of managerial skill that causes an employee to "save up" all their grievances to the point where they feel the only way to get what they want is through essentially dropping a bomb on their manager.