The Camera Was On Its Own
As soon as Adam entered the room, he noticed that the camera was already pointing in his direction and was slowly moving towards him. Adam also noticed that the camera was slowly creeping closer to him. Adam also observed that the camera was gradually moving closer and closer to him. And Adam also saw that the camera was moving toward him as he entered the room, bringing it into a proximity that was closer to him than it had been previously.
He also noticed that as the video was being taken, the camera was moving in a direction that brought it closer and closer to him. The series of events that took place after that point was very similar to a scenario from a movie that was either exciting or horrifying, depending on your point of view.