No, there are ways to remove metadata from images, and other files.Oh that's pretty clever. And i'm guessing if anyone, even a single person, uses a leaked care package and doesn't delete that chunk of code in the gui.rpy the leaker will get flagged... that's terribly clever... but i have to imagine that wouldn't be too hard to mess with before uploading the leaked files publicly no?
If future leakers just remove all metadata from images all will be fine.