I figured it out.
The window which was opened had to call the tinyMCEPopup.close() in its own scope. Which also meant I had to include the tiny_mce_popup.js script as well.
I figured it out.
The window which was opened had to call the tinyMCEPopup.close() in its own scope. Which also meant I had to include the tiny_mce_popup.js script as well.