Lots can change in 4 years, including demos with 'GetRadWindow' - I went through the demos and couldn't find the referenced bit of code (which is sad, I could have really used it in my project...).
However! The Google never forgets, so for future reference for fellow coders, here's the entire code snippet. I had to change the Sys.Application.add_load to window.onload, but other than that, everything worked like a gem for me!
window.onload = RedirectIfInRadWindow();
rWnd = GetRadWindow();
// redirect parent page to current url
rWnd.BrowserWindow.location = window.location;
// close RadWindow
oWindow = window.radWindow;
oWindow = window.frameElement.radWindow;