Reverse The Polarity Of The Urine Flow

So I was watching clips of classic Doctor Who on YouTube today, and this happened:

In this clip from the episode The Time Monster, we see the Third Doctor and Jo Grant are inside the TARDIS. Note that the Doctor's holding some kind of high-tech device...

Here's a closeup of the device. Um... OK, then. This had to be the work of a disgruntled prop man at the BBC, right? I mean there's no way this happened by accident. Some worker got pissed at management and decided to see if he could sneak a giant dick on the air in 1972.