Dumbledore's Look of Triumph re: WHERE Harry was cut

[rachaelmcadams]

No: HPFGUIDX 155239

I was just re-reading GoF and I noticed that when Harry talks about 
Wormtail cutting his arm, Dumbledore wants to look at it and where 
he's cut:

"Dumbledore walked around the desk and told Harry to stretch out his 
arm.  Harry showed them both the place where his robes were torn, and 
the cut beneath them." (p.604, British version)

After that Harry tells them what Voldemort told him and then comes 
Dumbledore's infamous gleam.

>From the graveyard scene, we learn that the cut is in the crook of his 
right arm (p.557).  

Now, I have no idea what this means, but since Rowling mentioned that 
we should look into the triumph once more, I thought it was worth 
considering and wondered if anyone else had any ideas about it. I 
didn't think anyone had discussed the place of the cut as having any 
importance, but Dumbledore does feel the need to inspect it.

Any theories here?