When Rebecca and Marcus are walking hand in hand on the beach after drinking wine with his colleagues, the second shot is a frontal medium shot. In the upper left part of the shot, the sound operator's boom microphone is briefly, but clearly visible.
(at around 1h 29 Mins) Just after she calls hello in the empty house and walks out to see if anybody is in the garden, to the far right by the tree you can see several people standing; next second when she gets there, they are gone.