“This utility modifies the behavior of the drive to wait longer before positioning the heads in their park position and turning off unnecessary electronics.”
Which of the following command line options did you use? If you used “-dall”, then one would hope that the tool would have correctly determined whether your drives were “applicable”, in which case one would expect that no harm would have been done.
C:\>wd5741 -?
WD5741 Version 1
Update Drive
Copyright (C) 2013 Western Digital Corporation
Syntax:
WD5741 [-d?] [-dn] [-dall] [-s] [-bn] [-?]
where
-s Stop updating on first failure
-bn Set maximum bytes per command (default=512)
-d? List available drives
-dn Update the specified drive
-dall Update all applicable drives
-? This help message
I believe the demo version can read all the firmware modules. If you can ZIP these MODs and upload them, I will be happy to analyse them for you. I suspect that the changes would have been written to MOD 02, in which case there may be a backup MOD which would have the original data.