Check out the 8/8 Angels vs. Yankees game: http://www.stubhub.com/los-angeles-angels-tickets/angels-vs-yankees-8-8-2008-505253/
Normally, only season ticket holders can list their tickets for instant delivery. At the same time, the left field pavillion is not open to season ticket holders (there are a few holdouts from the old days, but not many).
Now check out the 8/8 Angels vs. Yankees game on Stubhub. There are over 400 listings in the left field pavillion with instant delivery. The listings are all priced similarly and at $5 intervals and have very similar notes.
Is there another explanation for this or is it indeed obvious that the Angels are scalping their own tickets without putting them on the primary market?