Oh yes, my daughter got something of the sort. She was accused of plagiarising an essay, that she'd written, because a different lecturer had set the same subject for an essay the previous year*. She hadn't even used that one as a source, just that the new version used many of the same sets of arguments and evidence. Because it had to. They took their time before admitting it, though.
*It was one of those areas that is covered within two different course components, in different modules at different times or something like that.
Biting the hand that feeds IT
