GH4 Audio Sync Issue? More Likely a Playback Codec Issue...Maybe

Dave Dugdale hit me with a great question the other day--are we seeing any audio sync issues with the audio recorded by the GH4? What he described is that it seems like the video and audio are off by a frame and a half or so. I sat down and ran through a few tests and to me, it's looking like the GH4 is capturing the video and sound in sync but that some players are having a hard time playing back with them in sync. Strange... Are any of you seeing this issue?