I tried the way it was mentioned in the showcase as well as in your code but does not work fully so i tried another approach lets have look
Facelets
<p:growl id="growl" showDetail="true" />
<p:tabView id="tabView" binding="#{homeBean.tabView}" >
<p:ajax event="tabClose" listener="#{homeBean.onTabClose}" update=":form:growl"/>
</p:tabView>
Managed Bean
private TabView tabView = new TabView();
Tab tab1 = new Tab();
tab1.setClosable(true);
tab1.setTitle("Business Partner");
Tab tab2 = new Tab();
tab2.setClosable(true);
tab2.setTitle("Manage Favorites");
tabView.getChildren().add(tab1);
tabView.getChildren().add(tab2);
now it seems to be working. Note : I used Primefaces 5.0