To my understanding (I hope someone corrects me if I am wrong) the only was to access the game data is when the game partition is "unlocked".
Normally mounting the disc image or the game only gives you access to the L0 video partition. If you use either a kreon drive (or hotswap method) you can unlock the game partition for dumping. I have never dabbled with this myself (neither my old console or my new one is modded, I only mod for friends) so I can't even speculate as to whether or not it's possible to modify the game partition during the dumping process.
I do know, however, that AnyDVD is capable of corrupting the game data, which in itself is a POC. (Proof Of Concept)
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning ~ Rich Cook
All you need is the ISO file from a game. Open it up with one of many x360iso browser programs and you can extract any information you want from it. Whether they be videos, sounds, .bmp or even things that you can't even utilize without a dev kit. For instance you can get the l4d intro out of the l4d iso. I hope this answers your question.