Ri-i-i-i-ight. Here's an experiment for DU folk physically capable of running (not entirely an insult, as I'm only marginally so). Run a 50 yard sprint twice, timing yourself both times: the first time, run it standing up straight; the second time, run it in the leaning forward position that will feel more natural. Which time was better? Similarly, Brown, in trying to rush Officer Wilson, would have been leaning forward, which would account for the downward travel angle of the first shot to his head (another possibility is that the bullet was deflected by a bone in Brown's skull).
Maybe the reason the coroner (the Brown family's coroner?) didn't highlight this as a "damning" detail is that he recognized that is is easily explained.
Besides, if, as this DU fool suggests, Officer Brown shot this shot when Brown was on the ground:
* What caused Brown to fall? None of the shots to the arm would have that effect (except in a cheesy Hollyweird movie);
* If Officer Wilson was standing over Brown at an angle that could produce that angle of travel for the bullet, why did he then bend over in a way that could account for the other head shot entry? In the presence of Brown's buddy and other potentially hostile bystanders?
The more details come out and the more one thinks of the details' meaning, the more one realizes that Officer Wilson's account fits the physical evidence. Brown tried to rush Officer Wilson: his motion caused bullets aimed at his torso to hit his arm; he was leaning forward as a running person would, accounting for the angle of travel of the first head shot; he was falling due to that first head shot, accounting for the entry point of the second head shot.
That seems a likely reconstruction of the event to me, at least.