Brian doesnt have much support that I know of, just a really fast local guy.
I know the RM last year only had a pipe and silencer, with some head work, stock otherwise, so I would imagine the YZ125 was not the trickest thing out there it didnt look like it.
With a better engine and stuff he probably would have made it, either way he is a bad ass for trying, no one has tried a 125 for a while.