I've flashed my 05 WELL over 100 times via open source using the same steps you've posted here, and have never had a problem. The closest I have ever come to a bricked ECU was when I flashed the car when the battery was low, and about halfway through the flash it started dumping out a mess of errors and then failed. I just left the key on, hooked up a battery charger, and flashed it again and it was fine.
The main difference between what I do and what I see here, is that I've never directly flashed an emailed or otherwise downloaded ROM onto my ECU. I always open the downloaded ROM and a bone stock ROM in RomRaider/ECUFlash, copy/paste the necessary tables over, and then flash that. I couldn't really tell you why. Even patches like SD, LC, or FFS...I always patch a vanilla ROM, and then copy the tuned tables into it using RR/ECUFlash before flashing.
A corrupt ROM image is the only thing I can think of for your situation at this point.