More editing issues. Or in this case out and out deception. Eric and Adam are in the Concert Hall and they do the SFT again. The light goes out twice, but if you look carefully it's the same scene replayed. Watch the reflection of the cameraman's IR illuminator (I think that is what we are seeing) It is a bright circular region on the table in front of the main light. It's possible it is a reflection of the light itself and moves because the cameraman moves.

Regardless, watch it's motion with respect to the counting. The light moves around in the same pattern which would be pretty hard to do twice in a row.

At the word "three" the reflected light appears to move closer toward the bottom of the screen, there is a pause, and the light turns out. It does this in the same fashion and after the word "three" (including the same length of pause) each time.

Edited: More confirmation. The first time Eric is standing. The second time he is in a hunkered down position. The way he has his recorder held in the second shot it casts a shadow on to the table that would be visible in the direct shot of the flashlight (which doesn't include Eric in the shot) The shadow of his arm and the recorder are no where to be seen in the second shot…so it's simply the first shot spliced in again to make it look like the light went off again.

Also look at the VERY top center of the screen each time the "going off" sequence starts. There is a very bright "barred" reflection (4 bright spots each separated by a dark band) in the same position each time.

The scene is spliced to make it appear that the light is actually going on and off in response to the Cadets. The light CAN go on and off by itself if set correctly, but they splice in the timing to GIVE THE IMPRESSION of interaction.

The Doctor said:

One has to wonder if shots of the flashlights going on and off might be the reversing of the frames.

I know for a fact that some of the flashlight scenes where it goes off are the same as other ones where it goes off…repeating footage to deceive. Showing the reverse of a "going on" to depict a "going off" is very possible and my only hesitation of accepting it fully is that, given what we've seen of the atrocious editing, I don't know if the editors are smart enough to play footage backward! lol