Hi Terabyte,
The 'double confirmation' on Test Day is there as a counter to anyone who would argue that they "accidentally" chose an answer. While it's possible that you might 'accidentally' hit the submit button, there's no plausible argument for why you might accidentally hit that button AND THEN accidentally move the mouse and hit another button. In addition, this aspect of the Exam has been a standard part of all Test Taker's GMATs over the last 5 years, so changing that aspect of the Exam would likely impact (in some notable ways) the experiences for anyone who didn't have to repeatedly push it.
GMAT assassins aren't born, they're made,
Rich