Absent the GT-R owner verifying mods, there's another way to find out.
Joe will be at the Shift-S3ctor event, and there are plenty of GT-R's signed up, including a few 2013's....some stock and some modded.
Daily: 2013 e92 M3 MW FR DCT ZCP / ESS VT2 650 S/C, MRF mid/Akra slip, ST BBK
Track/Airstrip: 2011 997.2 Turbo S PDK / 501 AWHP & 536 AWTQ Bone stock on a Mustang dyno
Beater: 2013 X5 3.5sport