I see your point, and agree about the kind of world that I want to live in, but if I may be allowed to play devils advocate for a moment:

Just spitballing here but what if the software decrypted something as a side effect of doing something else like watching a movie. After all, buggy software is everywhere, perhaps that is just a bug.

What if that random file was a test input for a software fuzzing test. Is that not a plausible enough excuse?

What if the system periodically accessed data files [that had random data] to verify their integrity, you never know when data corruption might sneak in after all.

I totally agree that anyone trying to plead this case in court would likely fail miserably but the though experiment is interesting.