The computer detected that a collision will occur as the cyclist went directly into the path of the automobile. The driver is given the chance to slow down or stop but if the computer detects no brake input from the driver, it will decide to intervene at the last possible second. Knowing how quick the car can stop and given the speed of the car and the cyclist, the car will automatically brake and stop itself to avoid hitting the cyclist. This is the true asset of the Collision Avoidance System.
A similar system is now in place in many vehicles in the form of avoiding collision with other cars. Mtbr and Carreview have driven many of these systems and they actually work.