I've had the car for a little over a month and have about 1600 miles on it. I've just started to push it after break-in and I noticed this for the first time yesterday going onto an on-ramp. I have the base model, no sports package, no sync rev, so that takes out sync rev as the culprit.
I was approaching the on ramp pretty fast in 3rd, I rev-matched and put it into second at about 4k rmp (possibly higher), the car was in gear before I took the turn and noticed it's not engine breaking for s***! I almost went into the f'ing curb and if I wasn't somewhat experienced I probably would have.
This being a heavy flywheel issue SOMEWHAT makes sense from the way it felt. Like the flywheel was spinning and because it's heavy its momentum kept carrying the gear? F! I don't f'in know.