As Florence starts chasing members of the congregation out of the church at the beginning, members of the choir can be seen getting up and walking forward in the direction of the aisle (note the young blond woman in the black dress who is first in line). When the scene cuts to a closeup on Florence moving down the aisle, the choir members still are seated in their places. They then get up and file out in the same direction as in the previous shot.
When Mrs. Higgings rushes into the dressing room to tell Florence about the 'miracle', the shadow of the boom mic can be spotted falling across her arm.