I think this is calls momentum. Unless you guys shift it to a very low gear, where the rpm needs to maintain the same speed is significantly more, then you will likely not see engine breaking just by lifting off the pedal. Example: just accelerate, downhill, level pavement, etc.
As speedworks described, he takes a turn at a significant speed, that speed will maintain because of the angular momentum. Not sure what gear he is normally in, but if taking a sharp turn at like 4th or 5th gear going 65mph, simply lifting of the gas pedal will not slow the car down because the rpm needs to maintain the speed is still low. This is just an example.
