I thought the P-39 would win by a wide margin, too. This outcome surprised me.
I too was in momentary shock when I checked the website and found out.
IMO, it was certainly the name recognition factor among the players who are not WWII aviation experts. If you didn't know either plane very well and read the wikipedia link for these two, well lets just say the outcome is now a no-brainer. For instance: Line two of the P-39 Wikipedia page says "handicapped", whereas on the B-25 page the first thing you read is "used with devastating effect".
Don't get me wrong, there are plenty of guys that know the Mitchell and wanted it without reading up on it and their reasons are sound, but I'd be willing to bet that the bulk of the folks that voted for the P39 are more well read on the subject of aviation. I'd be willing to bet the time logged on a per user basis in AH for the P39 voters is higher than the B-25 voters. I'd also be willing to bet that their $14.95 still only bought 1 vote nonetheless.
Having said that, the vote was a nice gesture and much appreciated. I look forward to my Mitchell test drive

Here's to HTC putting the P-39 and A-26 next on the list:aok
Magoo