but it can't be done without your method as on OP..
how i got bricked !!! my Moto g dual (indian)
i tried to downgrade from 4.4.4 to 4.4.2 to flash custom Rom and got system partition corrupt.
again i tried to flash stock images but no use, actual problem was System and data was not formatting.
even if you try million times and you can never successfully flash stock images without error..
however i was checking many threads in xda to resolve this problem but couldn't figured it out, as i was not new to XDA i had confidence that i can come out from this issue. until this thread gave me a hint but not a solution but still this thread is a part of the solution :P
let come to the unbricking method (only for those who cant flash Stock firmware from fastboot)
Reboot to fastboot..
flash Philz recovery first. get it from here.. http://forum.xda-developers.com/show....php?t=2639626
better to use Kernel Flasher by my old buddy Ghostfreak NB http://forum.xda-developers.com/show....php?t=2214724,
you just need to extract and copy the recovery to extracted kernel Kernel_Flashing_Tool_v2.0 in IMG folder and run kernel Kernel_Flashing_Tool_v2.0.bat.
press 1 and it will flash recovery, press enter it will reboot to Philz recovery,
now format System, data and whatever you can!!\
next reboot to Bootloader from Recovery,
and then follow procedure as OP
if you want to flash stock rom get from here http://forum.xda-developers.com/moto...k-rom-t2804891 and adb push as advise by OP. now you have stock rom running without any issues
You can also flash custom ROMs with ease.
Note you better flash recovery through kernel flasher tool..