A DESCRIPTION OF THE PROBLEM :
There is still a memory leak in the scene when it comes to MouseHandler. There already is a bugfix that considers most of the use cases (see links down below) but one scenario is missing:
If you start dragging a cell of a tableview the fullPDRTmpTargetWrapper field of the scene keeps holding on to the reference of the tableview even when its gone and the GC was triggered.

https://github.com/openjdk/jfx/pull/448
https://bugs.openjdk.java.net/browse/JDK-8264330

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
- drag a cell
- push button 'Remove Pane'
- trigger GC

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
no remaining reference to the tableview
ACTUAL -
fullPDRTmpTargetWrapper still has a reference to the tableview

---------- BEGIN SOURCE ----------
package com.arm.ablex.client.fx.main;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class MemoryLeak extends Application {

    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(Stage stage) throws Exception {
        Button buttonRemove = new Button("Remove Pane");
        VBox box = new VBox(buildTableView(), buttonRemove);

        Scene scene = new Scene(box);
        buttonRemove.setOnAction(event -> scene.setRoot(new Pane()));

        stage.setWidth(1000);
        stage.setScene(scene);
        stage.show();
    }

    private TableView buildTableView() {
        TableView<String> tableView = new TableView();

        TableColumn<String, String> column = new TableColumn<>("column");
        column.setCellValueFactory(param -> new SimpleStringProperty(param.getValue()));
        column.setCellFactory(param -> {
            TableCell<String, String> cell = new TableCell<>() {
                @Override
                protected void updateItem(String item, boolean empty) {
                    super.updateItem(item, empty);
                    if (!empty) {
                        setText(item);
                        setOnDragDetected(event -> {
                            startFullDrag();
                            System.out.println("this causes memory leak");
                        });
                    } else {
                        setText(null);
                        setOnDragDetected(null);
                    }
                }
            };

            return cell;
        });

        tableView.getColumns().add(column);
        tableView.getItems().addAll("item1", "item2", "item3");

        return tableView;
    }
}
---------- END SOURCE ----------

FREQUENCY : always