We did not have any outages on those dates. You can check the status of Kami using this link:
Can you have the student check the tracked copies of the file, to see if they accidentally created a new copy of the file?
You can check by selecting the Open file button in the top right, which looks like a folder icon. At the bottom of the drop-down menu there will be a header titled Tracked copies that will house any copies of the file that may have been created.