Adaptive Equipment problems of the 2015 Ford Fusion Hybrid

Good afternoon, I want to bring this to your attention. I don't know if it's a problem with Ford or with me. So please bear with me. I just purchased the above vehicle about 3 weeks ago. It is brand new. This vehicle comes with a feature called "active park assist. " it is new to me and have never owned a vehicle with this feature previously. Yesterday, I used it for the first time. I turned it on and let it parallel park for me. I followed the directions on the vehicle video screen and took my hands of the wheel. The vehicle then backed into the space and struck the car parked behind. Needless to say, I was stunned. The directions in Ford's manual are somewhat, at least from my perspective, unclear. On page 180, it says "the driver is responsible for avoiding hazards and maintaining a safe distance and speed, even when the system is in use. " on page 182, the manual states "if your vehicle speed exceeds 6mph, the system switches off and you need to take full control of your vehicle. " I'm still unclear as to whether the brakes are operated by the vehicle during parking assist or me. For now, I'm not using it. Thank you for looking at this. Regards,.