This was deliberate.
2 seconds sound clip from The Master (1984) - A Place to Call Home (S1E14) sitcom.
You can hear this line at 00:17:44.280 in the Blu-ray version of the TV Series.
Quote context
[...]
- Old ninja trick. I wasn't sure I'd learned it.
- This is all my fault. I told these kids not to play in there. We store fuel in there.
- I'll get them into the mission.
- And call a doctor. Bobby could be busted up inside.
- Here, take them inside. I'll be right there. Come on.
[...]