Peak audio levels in DV?

Coming from an audio background where it is the norm to try and master recordings as close to 0dBFS as possible, it is interesting to note that Young, R (2006) "Easy Guide to Final Cut Pro 5" states that DV audio should peak at -12dBFS?

This is an interesting issue as in a previous post it was discussed that the 0dB indicator on a field mixer (in this case the Sound Devices 302) should correspond to -20dBFS on the DV camera, thus allowing for 20dB of headroom for peaks. However, if DV audio should really only peak at -12dBFS, this really only provides for 8dB of headroom. In practice, probably what would happen is that the full 20dB of headroom was made availale during recording and then compressed / limited down to peaks at -12dBFS during the post production phase.