Request for Advice: Genuine or Plagiarized? :)

In a MOOC assignment, I was required to peer-assess a student's submission. I received her feedback claiming that my comment was a plagiarism. In fact, I was genuine. Can you advise if my comment is sufficient to be genuine, or if not, how should I rephrase it?

My peer assessment
{
You made a good attempt to answer E-tivity 1. However, you probably have misunderstood how a research question should look like.

A research question is one and only one question. A research question guides and centers your research. It should be clear and focused, as well as synthesize multiple sources to present your unique argument. You may want to refer to http://twp.duke.edu/uploads/media_items/research-questions.original.pdf and http://libguides.lmu.edu/content.php?pid=10084&sid=1965230 for guides on how to narrow down your topic and formulate a good research question which is one-sentence long.

Keep up your hard work
}

The student's feedback
{
This is Plagiarism. Thanks for the link you copied from.

"A research question guides and centers your research. It should be clear and focused, as well as synthesize

multiple sources to present your unique argument" - Source: http://twp.duke.edu/uploads/media_items/research-questions.original.pdf
}