Well, if you have any experience with traditional programming frameworks, you will see nothing like Flash around... and the Flash IDE (the software tool) is more of a way for designers to "visually program" by using tools they are familiar with. So the programmer in who did the Actionscript for this should never have placed code in the visual editor, and especially should not have use 10 layers of Actionscript code... that is just is just a debuging nightmare...
If all of the code where at the very least in one frame on one layer, then debugging would be much easier.
here is an older link, but the same theory applies...
http://www.adobe.com/devnet/flash/whitepapers/actionscript_standards.pdfrp / ZA