you're probably right. but lets look a couple things.
to do that, you'll have to stop, shift to r and gas, at the same time, either turning your head looking back or using the mirrors to look back. that takes time. of course, it has to do with your driving skills too. some, I know can't back up as well as moving forward. some, can drive backward as good as forward. all that takes time. and when it comes down to life and death situations, time is of the essence. wouldn't you think would be faster just to gas it. also, good thing there wasn't a vehicle coming right around the curve.
another thing to look at is, we don't know the road after the cop car. does it curve to the left(from the suv driver's point of view), does it go straight, or does it curve to the right. curving to the left would definitely put driver of the suv in the bullets travel. straight, still iffy. curving to the right, should be safe due to travel away from the bullets of the gun man.