If ever we see a situation where an implicit lock is active, going to “Edit Properties” on the document (which requires checkout) is the only way I know to get the actual NAME of the person with the implicit lock.
Now if the user comes back and says she has closed Excel we still need to check because Excel and Outlook might be in a zombie state (running in Task Manager Process tab, but without having any visible windows on the desktop) In these rare cases the lurking EXE may still have the SharePoint file open over the network. So even though the end user swears she is no longer editing the file, the Windows client may still have the fill open and would be continually refreshing, thus maintaining the implicit lock. Sometimes we may need to have the end user reboot to release the zombie held lock.
NOTE:: The lock can be removed only by that user and only through the system used to place the lock.