I believe that hack incorporates a modification to the audio levels called Pasadena Pulse Audio. It makes cleaner audio recordings possible, but the AGC behaves differently from the stock settings.

As I understand from my experience with patches Flowmotion v2 (and some others) contain an audio patch:

Pasadena Pulse Audio Patch V2 B2, thanks to Per Lichtman.

from http://www.personal-view.com/talks/discussion/3337/gh2-flow-motion-v2-100mbps-fast-action-performance-reliability-for-class-10-sd-cards/p1

Description of this audio patch that is incorporated into the Flowmotion v2 patch: http://perlichtman.com/pasdenapulse/wordpress/2012/03/14/panasonic-gh2-audio-settings-file-pasadena-pulse-audio-v2-beta-2/

The top line is that the top 2 metering blocks which appear in red are not over modulating when using this audio patch, they are useable audio, this extends the range of useable audio the meters can show, and if you don't know this and set your levels as you did without running this audio hack, trying to keep your levels from going into the red, I can presume one may encounter the audio levels may have an overall lower output.