Factual error: During the scene when Harry and Hagrid are on the motorbike going through a tunnel, the bus signals that it is going to Dartford. Both of the tunnels at Dartford carry north-bound traffic, going away from Dartford - all south-bound traffic, towards Dartford, travels on the bridge (visible in some shots). No traffic enters the tunnels heading south-bound towards Dartford.
Suggested correction: During times of high winds, the Dartford Bridge is closed, and one of the tunnels does, in fact, carry southbound traffic.
Continuity mistake: When Harry sees into Voldemort's mind when he is Gregorovitch's wand shop, the wand Voldemort uses is the Elder wand, however Voldemort has not got the Elder wand yet. (01:07:54)
Suggested correction: Voldemort is not carrying the Elder wand, but his own wand. You see glimpses of the Elder Wand in the hands of a young Grindelwald though, perhaps you are confusing the scenes.
Other mistake: Harry pulls a knife out of Dobby's chest, but before that, we can see there's no knife.
Suggested correction: Yes there is, Dobby is holding on to it as he falls into Harry's hands. Its not totally obvious, but the CGI people definitely put it in.
