VM
Seems like a plausible explanation - when it comes back, we briefly see the film before it goes to the breakdown slide. I think the film has continued playing during the fault and has then been paused - as obviously the video was okay, even if there was no sound when they tried to go back to it.
Could it have been an electrical fault, that then caused something in the Pres suite on BBC1 to trip? Certainly, when we hear Andy Taylor the first time, it sounds like static electricity is causing the sound distortion.
Seems like a plausible explanation - when it comes back, we briefly see the film before it goes to the breakdown slide. I think the film has continued playing during the fault and has then been paused - as obviously the video was okay, even if there was no sound when they tried to go back to it.