In the canteen, after Winston has said goodbye to Syme, the camera settles back on him and moves forward, bumping into the dining table in the process.
When Winston Smith presses the door shut after departing Parsons, the entire set wall wobbles.
There are a number of what appear to be "Fails" ('Equipment/Crew Visible' or 'Revealing Errors' and similar), however it must be remembered that this programme, in common with a lot of BBC output at the time, was broadcast as a Live Performance, being recorded for later repeats. Any such errors are therefore totally to be expected, and would be the same as if the show had been performed on a theatre stage before a live audience.
When Winston Smith returns to his workstation and puts his glasses on in the first minutes of the film, a microphone boom shadow is clearly visible,