I'm an Aussie too and I've got serious doubts as to whether it's legit.
I'll gladly eat my words if I'm wrong as I'd love to see the record in the name of an Aussie but the footage I saw showed him missing reps as his chin wasn't clearing the bar. That was on a 9 network news report. The youtube footage I looked at last night seemed to indicate some missed reps too although it didn't look as conclusive as the news report footage.
The first footage I saw on the news was shot from the front and slightly below the bar and appeared like every rep was incomplete, no was announcing no counts or anything similar so I assume those reps were counted. I could be wrong there as I don't know how those events are managed.
Here's the youtube footage. at around 2.13 it shows a side on shot with some reps I wouldn't have counted (there's a reflection coming from a pipe behind the bar at bar height and his chin appears to not attain that height a few times). There's also a shot from the front that seem borderline as the camera appears to be below the bar. Around 2.30 seems to show some missed reps too.
I can't find the footage from the news report that showed almost every rep to be a no count. I did find this on youtube that seems to show he has a bit of a kick in his technique which could well be within the rules but seems like a bit of assistance others trying their hand at the record didn't use. I can't state that he used that kick in the record attempt though. I can't find any footage of the attempt showing the lower half of his body.
Any way you look at it, it's still a superhuman feat of endurance but I'd like to see more footage of it. I thought the whole thing had to be shot from 2 different camera angles.