<p>If the school used turnitin.com and your own work came up as being plagiarized, it's technically still plagiarism. This is due to the TOC of the program, where when you submit a document, the document becomes turnitin's property. That is to say, your essay is technically no longer "your" essay. And hence, instead of reciting your own work, you plagiarized off turnitin's work.</p>
<p>One of the leading criticisms against turnitin would be this rather obscure transfer of copyright.</p>