Trigger page message in the parent page from the Controller Extension of a custom list view button

Question

Is there any way to trigger the display of a page message in the embedding Detail page from the Controller Extension of a Custom list view button?

I create my list view buttons with this technique and as this uses seperate pages per button the page messages created in the Controller Extension seems to land in them and NOT in the displaying detail page.

Page

<apex:page standardController="Contact" extensions="ContactAction_CtrlExt"   
           recordSetVar="contacts" action="{!doAction}">

</apex:page>

Controller class

public with sharing class ContactAction_CtrlExt {

    ...

    public PageReference doAction() {
       ...
       ApexPages.addMessage( new ApexPages.Message(severity, 'THIS WILL NOT APPEAR IN PARENT PAGE') );
    }   
}