ABX, I believe option 1 is close to the mark.
After WW2, learning to fly was something of a fashionable thing to do, albeit one that required a bit of money.The V Tail Bonanzas were also something of a fashionable item at the time as well. So you had lots of professional people (the Dr bit) learning to fly in things such as Piper Cubs, Tiger Moths etc etc and then, because they had the income, buying their own V Tail, a much more complex and higher performance aircraft, and people died as a result of inexperience/lack of ability. Hence "The Fork Tailed Dr Killer" nickname.
At least, thats how it was explained to me, many moons ago!
