I agree with this. I think it's unfair that a guy who unknowingly plagiarizes gets auto-failed for the class.
How do you unknowingly plagiarize?
Zelig took the words right off my keyboard.
It might be possible to unknowingly plagiarize if you're not familiar with a lot of the material already available on the subject you're writing about.
Example: A friend of mine entered a short story contest some years ago. She'd always wanted to try writing science fiction and decided to go for it. She was furious and more than a little in tears when the critique came back from the judges that they thought she'd plagiarized most of the story. My friend gave it to me to read, expecting me to agree with her position that she hadn't plagiarized it.
Unfortunately, the story my friend wrote had numerous elements of several fairly well-known science fiction stories. I told her so, but explained it this way: Because my friend hadn't
read much science fiction, she was therefore unfamiliar with those stories and had thought up very similar story elements. So she hadn't
deliberately plagiarized. But the end result was a story that was far too close to material already published, so her story had to be disqualified. I advised her to read more so she'd be more familiar with what had already been done, and try again.
Even David Gerrold, creator of the Tribbles, got into a mess with unintentional plagiarism. He'd read a Heinlein story quite some time before, and had forgotten it by the time he started writing for Star Trek. His Tribbles were very close in concept to the Martian Flat Cats of Heinlein's novel
The Rolling Stones. The producers of Star Trek had to cover their legal behinds by asking Heinlein's permission to allow the episode to be filmed.
However, in academic circles, I would be very suspicious of somebody claiming they didn't know something was plagiarized. If they hadn't thought up the idea all by themselves, somebody else did. And that somebody else needs to be credited. To do anything else is dishonest.