As a proud Aussie, I can say that I don't much like Down Under, and I'm not a huge Met At Work fan anyway. The song is fine, not their best song... but perfectly catchy. Now, I will say the big hook of the song is centred around that flute riff, and that flute riff is undoubtedly quoting Kookaburra. Of course, it's quoted out of context, shifted into a different chord progression, and is really unrecognisable unless you know what you're looking for. Like the guitar solo in Oasis' Supersonic is a perfect lift from My Sweet Lord, but rendered unrecognisable by its context, and Noel had to explain to everyone what it was and how clever it was.
As for finding against the songwriters, that's just weird, as the flute riff is not a part of the published song... it's part of the arrangement, added by a flute player who does not have a writing credit. Tricky!
Quoting... it's an interesting subject. Oasis quoted My Sweet Lord, which was itself found to be a rip-off. But Oasis quoted the guitar solo, which isn't part of the published song either. Yay. Puccini swiped the US National Anthem. Eric Carmen lifted Rachmaninov *twice*. Happy Mondays nicked Hendrix; Little Steve Wonder took Mary Had A Little Lamb; the Beatles borrowed another anthem, plus JS Bach and Glenn Miller all in the one track. The Supremes had multiple hits with a single rhythm track. Huey Lewis, M, and Ray Parker all released the same song with different vocals on top, and I'm sure that Pink, Kelly Clarkson and the Veronicas have all just released the exact same track under different names.
La plus ca change...
Anyway, my understanding is that the ruling is for 5% of royalties from the time that Larrikin Records acquired the rights to Kookaburra (about 1999/2000?), including all future royalties as well. So this does not affect all the money made at the height of the song's success, and I don;t imagine that the songwriters will suffer too much.
A strange case.