I just read up about that. Never even heard it, but there's a comparison of the two riffs on youtube, and it's hard not to think one came from the other.
Still, Kukaburra is from the 30's, so he probably heard it as a kid and just riffed on it.
The royalties ended up being something like 5% of only a small portion of sales AFTER 2002 anyway, from what I read, so, meh.
Grey_area's right, though, that third album, ugh.