Going off-topic a bit, but I’ve heard similar tales of how continuity announcers unofficially slipped out of the building during a film, schools hours or Children’s ITV - some “moonlighting” by recording VOs or similar at a location elsewhere in the city. I suppose that was one reason you didn’t always get an apology during a breakdown!
In some regions, the same announcer stayed on shift from startup (as early as 8.30am in the pre-TVam days) until closedown (which was often as late as 1am). I expect they were officially supposed to be at their desk at all times except to answer calls of nature, and probably ate lunch and dinner in the booth?
The TTTV announcers were known to spend some of their time in the Egypt Cottage with a pager in their pocket...
It may be difficult to imagine this now, but there was a huge culture of drinking in the broadcasting industry going back a few years.
To single out the announcers is a little unfair, although as they were the familiar faces and voices of the stations, it is possibly not surprising.
Before mobile phones there would be the phone numbers of pubs where staff were likely to be on file - and I have been in pubs when the person behind the bar has taken a call and asked if there were any BBC engineers in there......
I really don't think that the broadcast industry was alone in that - associated trades - such as journalists and musicians didn't seem to be shy of a pint or two.
There were some extreme cases, going back to announcers, there were two who couldn't be rota'd on shift together as they would encourage each other to have yet another "bollocking pint".......