From what I've understood about evac-ing a coaster is that they are suppose to evac the first row they come to. So ideally they would evac the train from the last row to the front row on a lift hilll, there for you should never get stuck with exhaust blowing in your face.
I don't think it's flawed design. I think it was the team who was using it wrong. When used the way it is intended to be used, there shouldn't be a problem.