In the manual it explains how to use the VSC off switch. What is happening is VSC is still active, just the TRAC has been disabled.
First push the button while stopped, you'll see the "skid light" come on, the TRAC is now disabled. Next Press and hold the button for more than 3 sec, now the "VSC off" Light will come on. Now both TRAC and VSC are disabled. ATRAC is always active, but ATRAC does not cut throttle, it only tries to distribute power to all drive wheels evenly.
I attached a PDF that explains it in more detail than the owner's manual.
Hope this helps. Try again and go have fun.
