Is referencing a technical report in an improper format plagiarism? Suppose someone uses a report such as technical report in an article or school work, but in the references at the end of document they just reference it like:


  Author A, Author B, title, year


I.e., they write what google scholar provides and forget to put the institution and mentioning that it is technical report.

Is this plagiarism?
The point is that student already submitted the paper and changing it entails lots of emails and an official process, just want to ensure it is not educational misconduct.
No.  It's just poor citation writing. 

[Assuming this is the only issue.  If I open the report and your paper and see bulk copying of prose, that is plagiarism.  But it still would be even if your endnote was properly written.]