ListView: If code in delegate causes delegate to be removed, references break

qrc:/main.qml:27: ReferenceError: label is not defined

import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Controls 2.2
import QtQuick.Layouts 1.3

Window {
    visible: true
    width: 640
    height: 480

    ColumnLayout {
        anchors.fill: parent
        Label {
            id: label
            text: "This text should change"
        }
        ListView {
            id: listview
            Layout.fillWidth: true
            Layout.fillHeight: true
            model: 1
            delegate: Row {
                Button {
                    text: "Reset before set (doesn't work)"
                    onClicked: {
                        listview.model = 0
                        label.text = "Changed"
                    }
                }
                Button {
                    text: "Set before reset (works)"
                    onClicked: {
                        label.text = "Changed"
                        listview.model = 0
                    }
                }
            }
        }
    }
}