From the news clips at the time.....

Bremer goes into cheesy "Oh we have have one more speaker..." routine
From camera at the back you cant see who walks on stage but there is immediatley a huge roar and every single soldier stands up and cheers - despite the fact that 90% of em probably couldnt see the stage.
All of a sudden cameras are going off. Unless there was a HUGE contingent of press corps there, those cameras were soldiers' based on the number of flashes going off.
The soldiers right in front of the film camera is taking digital shots immediately.

I'm not saying the whole thing was staged.
I'm not saying the whole thing was rigged.
I'm only suggesting that the audience may have been tipped.......