I see it all the time and it's quite frustrating to see people being so naive. The law is not purely mathematical and algorithmic. I think a good example that moves outside of IP law is murder vs manslaughter. Two identical killings could fall under different charges simply due to what the killer was thinking at the time. And we want it that way. It would be unfair and not accomplish anything good to treat an accidental and an intentional killer the same way.
I don't know why you were downvoted because you are exactly on point. In the GP example, two files can be xor'ed to yield some pirated document. The poster thinks this would require the judicial system to punish the creators of both files equally because both files contribute bits equally. But the judicial system looks at intent, and only one of the files was created with criminal intent.
