I believe the reason he used a lower nitro content was to make the 5 minute mark where the other guys did not make it. That is why while not having the "fastest" motor out there, he was still able to TQ.

On why he did not use 40% for the final, that's beyond me. But I heard that with the No Fuel Bottle in the Pits rule, it was very difficult to tune the engine without getting the engine flame out the car and get hit by 1/8th scale cars practising at the same time.

I guess I kind of agree with you on what you're trying to say inexplicitly that it was a poor excuse of loosing. But I do agree that at the end of the day, the better drive won not because of the motor but because of skill as well.

Correct. Hence the motor theory speculation was correct to say that power wise, they were even as mentioned by Rene in his Pre-World report in Brazil. The fuel was the "determining factor".