Umounting filesystems mounted via NTFS-3G is not synchronous.
It is possible that NTFS-3g mount processes remain, and continue
writing to the underlying block device, even after umount has completed
successfully. To solve this, wait explicitly for all NTFS-3G mount
processes to terminate, before continuing.

Similarly, there is no guarantee that all of the cached data have
been flushed to disk when shutting down the system abruptly using
the 'o' sysrq key to shut off the system immediately.
To solve this, run "sync" explicitly before shutting system off,
assuming no other process is currently writing to the disk (see above).

The combination of these two issues could lead to data loss.