Comment 5 for bug 44886

seems finally to be fixed, quoting from the sshfs mailing list:

The sshfs team is happy to announce that this long standing bug is at
last being fixed. From the OpenSSH-4.9 release notes:

  * Added a protocol extension method "<email address hidden>" for
    sftp-server(8) to perform POSIX atomic rename() operations.
    (bz#1400)

Support for this extension is already in the sshfs CVS repository, and
will be released in the not too distant future.

Of course, this will only work if the server is upgraded to
OpenSSH-4.9 or later, otherwise one of the workarounds will have to be
used.