Using the sample in this link, I tried replacing the SWF file with one that has a Fullscreen button. It also has a listener that shows an alert box if ESC is pressed and restores to original size.
Clicking on the Fullscreen button shows the SWF in fullscreen, but pressing ESC does not restore the SWF to the original size.
The form has key preview set to false, so I'm not sure why the SWF is not responding to ESC.
I also tried setting key preview to true but, I don't get that keypress from the form either.