I remember more a "I'm dobbing" said with a distinct whine in the voice.
And I don't mean that Australians necessarily think that dobbing is a good thing, it's just the word itself is not pejorative. The Tax Office ran a "Dob in a tax cheat" campaign, but I can't imagine HRMC ever having a "Grass up a benefits scrounger" campaign. That's partly because you can't say "grass" with a Whitehall accent.
Took me quite a while to realise that "root" wasn't an obscenity in the UK, and I've only just sorted pavement/footpath/sidewalk.
(in Australia, footpath is the word for the pedestrian path that runs beside a road, while pavement is the actual surface, usually of the road itself. Yeah, so until quite recently I was very confused by "riding on the pavement", as in "where else? on the grass?")