void defaultSelected() {
		isDefault = true; 
		isUserDefined = false;
		currentFallthroughAddr = defaultFallthroughAddr;
		listener.stateChanged(null);
	}
The option for "use default" fallthrough was chosen.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/fallthrough/FallThroughModel.java