An unknown member of the Order?

[Wanda Sherratt]

No: HPFGUIDX 73788

When Harry first arrived at GP, he was sent upstairs to be with his 
friends while the OotP held their meeting downstairs.  I remember 
Molly said, "He's just arrived."  Are there any theories about who 
this "He" is?  I assumed it was Snape, especially as afterwards, he 
was at the center of the crowd in the hall downstairs.  It implied 
he held a position of some importance in the group.  But afterwards, 
I began to wonder.  Could there be another traitor in Voldemort's 
midst?  As so many people have pointed out, it's an open question 
just how effective a spy Snape could be - all those years working 
for Dumbledore, the testimony at Karkaroff's trial, when Dumbledore 
blew his cover (almost as if it didn't really matter anymore) - it's 
hard to believe Voldemort could seriously trust him again.  But 
perhaps he's a decoy; the untrusted spy who attracts attention to 
himself in order to divert Voldemort from the presence of the REAL 
spy.  I'm wondering if "he" is the one who has Voldemort's trust, 
who is providing the REAL information to Dumbledore, while Snape is 
the stalking horse.

Wanda