What silvery thing?

[fruhu]

No: HPFGUIDX 43619

In GoF chapter "The madness of Mr.Crouch", after Dumbledore arrived 
to the stunned Krum, he "raised his wand into the air and pointed it 
in the direction of Hagrid's cabin. Harry saw something silvery dart 
out of it and streak away through the trees like a ghostly bird".
 
What was it? Did the silvery thing dart out of Hagrid's cabin or 
Dumbledore's wand, or what?

Cheers,
Fru Hu / Freya