[giotto]

Because at 4:03 the tower is still there, and at 4:03 it is not. Clearly there was a section cut out. In my opinion, the voice-over sounds fake. On 9/11, no one said "Holy crap" when the tower fell. Almost everyone said either "Holy s#!+" or "Oh my God" or "F***" The audio voice-over in this tape sounds as if someone has added it to the revised video.

[Munz]

Looks more like they turned the camera off or paused it.
he says holy crap again at 4;16 and again at 4:38
It is a cop who knows that his tape will be reviewed.

later he does say holy GD .. but he says it as if he is trying to suppress it in his surprise.

They were doing work and the camera was paused. Nothing more.

[sauropod]

Maybe the guy with the camera had to change cassettes.

There is no “voice-over” that sounds any different than it did the first time I heard it. You’d have to ask the cop why he wasn’t as profane as you thought he should have been.

[Ramius]

So what? The guy had stopped the camera, and started recording again when he saw the second tower fall. What’s so mysterious about that?