If you see an error message stating that file is locked by the wrong user in excel, that's because there may be a corrupted Excel temporary file called the "owner file".
Please perform the following to solve this issue:
(Make sure that your view settings allow for hidden files and folders.)
Close the Document in question.
Open the folder where the Document is located.
Look for a hidden temporary file that looks like ~$filename.xlsx. It will start with a ~$ and otherwise reflect the filename in question.