Hi Peter, I answered this on the GTR forum after I asked Ev who said:
"The 2012 GT-R lap isn’t on the leaderboard because Tiff used the kerbs while setting the time. Not his fault – it was his first Track Battle for us and we hadn’t made him aware that we stay off the kerbs (to ensure consistency), so he did what any racer would do to get a fast lap!
Unfortunately we didn’t realise he’d made use of the kerbs until we checked the VBOX data and on-board video back in the office, and by that time it was too late to redo the laps. So while the comparison with the 991 Carrera S for that particular Track Battle was valid, it wouldn’t be fair to put the time recorded for either car on the leaderboard because they would appear faster than they should."
I've put it to the team that getting a 2012 or maybe 2013 figured according to protocols should be a priority, especially the 2008 model published may even have still had its 180km/h limiter in place!
However my car does get its laptime published in the next issue (17 and although it won't be on the leaderboard (being a modified car) I think the result was pretty stunning.