Or AppleScript, if you are on a Mac and the presentation will run on a Mac.
The theoretical answer would be:
Put an event message system on every page, that will fire, if the page will be changed to another page.
Meassure the time. And a process (going to a default page), that is invoked, if that will not happen in a period of time.
Or, more precise, put that event script on every button and fire, if the button is clicked.
But to get more help on that, you have to ask in the right Acrobat forum:
There could be a small chance to accomplish that with Flash and ActionScript 3 programming, too.
But this all is a bit out of my scope…