Got a Scare myself..
while playing with installing ClockWorkMod(CWM) Recovery (Shivakiran)
I played with the nvflash command (not good idea
After which I could not turn ON the Phone.
No Recovery Mode.. no Modes at all.
No Vibration when pressing the Power or (Power + Vol Up)
LCD not coming ON at all
Got me scared.. Pain to go to Service Center.
Then out of curiosity connected the Phone to Laptop.. and it was interesting to see NVIDIA Boot-recovery come up..
So opened NvMultiDown and Voila.. Flash started working.
Tried Steps for Installing ClockWorkMod(CWM) Recovery again..
and the same issue.
So flashed again using NvMultiDown
Now I am sure.. it is Difficult to Brick..