When Susan and Dave are talking after rock climbing, Dave's cup changes from his right hand to his left, and back again, between shots.
When Dave and Susan are in the coffee shop, Susan's hand can be seen on and off her cup between shots.
Right after the kidnapping, when Susan goes into the candy store; the Boom Mike and its operator can be seen right over Maya's left shoulder in the reflection on the right side of the stores window.
When Mark is shut out of the classroom by Mr. Griffin, the shadow of a boom mic can be seen above his head.