It is possible that files /etc/mtab and /proc/mounts don’t match. The first file is
based only on the mount command options, but the content of the second file also
depends on the kernel and others settings (e.g. remote NFS server. In particular
case the mount command may reports unreliable information about a NFS mount point
and the /proc/mounts file usually contains more reliable information.)
The other issue is that the /etc/mtab file for ntfs-3g is maintained by /sbin/mount.ntfs-3g.
man mount, section BUGS:
It is possible that files /etc/mtab and /proc/mounts don’t match. The first file is
based only on the mount command options, but the content of the second file also
depends on the kernel and others settings (e.g. remote NFS server. In particular
case the mount command may reports unreliable information about a NFS mount point
and the /proc/mounts file usually contains more reliable information.)
The other issue is that the /etc/mtab file for ntfs-3g is maintained by /sbin/mount. ntfs-3g.