Quoted from javagrind888:
With all the licenses Stern has, they didn't do this. It might not be malice, but I'd quickly blame it on pride or close mindedness before I'd believe it's a licensing issue.
It's not malice, they're using standard Linux imaging tools to make sure that software updates go smoothly. Using a laptop, a target drive, the same software, and a USB security key from a real machine, you can extract the image to the target drive. I haven't tried to replace a sound file and rebuild the image and try it on a game, but theoretically it's possible unless checksums are done on the original sound files.
Pre-emptively, I'm not interested in explaining how to do this, but I can let you know that at least on DI, extracting the image is possible. I think they used these tools because it's a time-tested, reliable to way to get large images to update on location.