During the 1972 Munich Olympics, some of the events that had been scheduled to air were cancelled due to terrorist activities. The pilot episode of was aired, without any advanced public notice, in order to fill one of the time slots unexpectedly left open due to these cancellations in the BBC schedule.

This episode previously only existed in a black and white version filmed for overseas sales, due to the BBC re-recording over the original colour tape in the 1980s.
But towards the end of 2009, a new technique was used to recover the lost colour information hidden in the b+w picture, resulting in a new colour-restored version which was shown on BBC2 in the UK on Jan 1 2010.

Humphries: Having trouble with Mrs Slocombe?  
Mash: Oh, all that women's lib's gone to her head, mate.
Humphries: Oh! I hope not. If she burns her bra we'll have to call out the London Fire Brigade!

Humphries: (Referring to Young Mr Grace) He's worth two million. 
Lucas: Two million?
Humphries: Mm, he can't take it with him.
Lucas: The way he's walking it looks as though he's carrying it on his back.

Lucas: (Referring to Young Mr Grace as he's leaving) Well that was a short day, wasn't it?
Humphries: Oh, I don't know; he's put in ten minutes. I wonder where he's going.
Lucas: I think it's a toss-up between the bank and the undertaker.

Slocombe: Look! What's me not having a baby got to do with him not taking his trousers down?

As soon as Mr Grace makes his exit, the camera switches to Mollie Sugden (Mrs Slocombe), who is waiting for her cue and is motionless for a second.
<Correction> She responds to the secretary on the phone (but her microphone is not on for a second) and then continues with her lines (which the microphone does catch). The sound man made the goof.