Cool video.
As a pool player I'd like to throw there some concepts.
In real life the angle after hitting the cusion is almost never the same angle (minute 1:00). It's not a "mirror", it depends on many factors:
The most obvious is the side spin of the cue ball. It's the easier way to change the output angle.
Another factor is how hard the cue ball hits the cusion. If the ball has a high speed the output angle will be lower, but if the ball hits the cusion so soft the angle will be higher.
The third factor would be the vertical spin of the ball. This is different from the other two points. The vertical spin won't have effect inmediatly after hitting the cusion, it will have effect on the ball until it loses the spin and starts rolling. So if the ball comes to the cusion with some vertical spin it will make a curve until the ball starts rolling.
Yeah, there are a lot of maths involved when playing pool! more than what many people can think. When you have been playing for many years you internalize a lot of concepts and don't need to make almost any calculation, but it takes so many years...
PS: It's hard to me to explain some concepts in english, sorry if you can't understand something I've wrote