Here's the thing with moire & aliasing...
ALL cameras have it. Even the 1D C and that is $12,000, and the Blackmagic Cinema Camera.
The 5D Mark II had much worse moire and aliasing than the GH3 and that didn't stop it being used by pros in Hollywood.
It isn't a desirable quality of the image but the way some guys have gone on about it on forums has been ridiculously over the top.
The list of cameras that the GH3 is better than for moire and aliasing is staggeringly long - 5D2, NEX 5N, NEX 5R, NEX 7, A99, D800, D600, 7D, 60D, 600D, 650D, EOS M, 550D, OM-D and nearly every other DSLR on the market.
The 5D3 is soft but when you sharpen in post sometimes you get some aliasing.
The GH2 had slightly less moire & aliasing than the GH3 given the same situation. But it still occasionally flared up. Not so much in the real world but with a very sharp lens with a very narrow band of fine patterns. You may get 1 occurrence out of every 100 shots with it. On the GH3 maybe you'll get 5 occurrences out of a 100. Depends what you're shooting. The 5D2 was doing it on roof tiles and water!! All sorts of stuff.
The GH3 seems to have a lighter anti-aliasing filter, so there's a very slightly wider window of fine patterns that it occurs on.
I hope this puts the GH3's moire into perspective. I know it can be a confusing issue, as it depends on so many different factors whether you get some or not. By the way, it is far less visible on a TV or projector than it is on a computer monitor - which is the least organic and cinematic way to watch video.