I took the flight planning exam as well, and I thought it was a bit of a tough papper, but the results will be out soon enough.
I did not get 4hr 6 min for that annex question, but most of the others in my group did, so i would be inclined to beleive that is the answer.
I think that the most interesting question was the first or second question which asked about the distance from a to c on annex a. What answer did you all come up with? I came up with 696 using departure, but a few others came up with 720 by using the NAP from the Jep Handbook