Where was/is the file stored? Was it on a network location? Try moving it to another location and opening it without renaming it. The lock file and user profile (as you indicate) are the usual methods to solve a basic file lock type of issue. If your computer crashed though you may be experiencing a network file permission issue or a lock by another process (such as the NFS lock daemon).
This is what it says in the
readmes/README_en-US file of the GNU/Linux download:
File locking is enabled by default in LibreOffice. On a network that uses the Network File System protocol (NFS), the locking daemon for NFS clients must be active. To disable file locking, edit the soffice script and change the line “export SAL_ENABLE_FILE_LOCKING” to “# export SAL_ENABLE_FILE_LOCKING”. If you disable file locking, the write access of a document is not restricted to the user who first opens the document.
Warning: The activated file locking feature can cause problems with Solaris 2.5.1 and 2.7 used in conjunction with Linux NFS 2.0. If your system environment has these parameters, we strongly recommend that you avoid using the file locking feature. Otherwise, LibreOffice will hang when you try to open a file from a NFS mounted directory from a Linux computer.