Yeah, knowing what exactly went on at the scene probably has more explanatory power vs the fact that E85 was pumped in. It is weird that a presumably German BMW driver isn't able to properly identify which side the fuel door is, which then begs the question, was it a German driver.
As far as E85 efficiency, I thought E85 can be well harnessed in turbocharged engines with reasonably high compression ratios, if the engine is specifically built/tuned for E85. Here's something that was tested on a vehicle from now defunct Saab, where more power was acheived with no penalty in efficiency:
Originally Posted by mkoesel
Emissions may be better (I don't know, honestly), but efficiency is generally worse.
So any decrease in emmisions on a per unit of fuel basis may be negated by the fact that you will probably need more fuel to cover the equivalent distance.
I am sure BMW has explored E85, and probably has ongoing tests involving the alternative fuel. But I have my doubts that the F80 M3 is part of this research.