I don't really have a lot of information to go on here (for reproducing, etc.) so I'm hoping this post reaches someone who's encountered this issue before.
What happened was that one file became 50-some files: (there are a lot more, but this gives you the general gist)
It seems that this might have been due to a UI glitch. I wasn't the person who uploaded the files, so perhaps my friend kind of accidentally had it selected and then Ctrl + dragged or something. But I think she was using her phone, where such a feature probably doesn't exist. It's clear that the duplication has happened multiple times, and it seems that those times line up with when she accessed the Drive app.
Any leads? We can delete the items, but we don't know if they mightn't just come back. (This has happened with a different file already, and that one got copied over 100 times.)