German Shepherd Attacks Pitbull [OFF LEASH DOG PARK] Part 1

Dog attack! A large German Shepherd viciously attacks pitbull/ American Bully while they are playing at the dog park! The pitbull/ American Bully has damage done to his eye during the crazy dog attack! Who's actually at fault in this dog park attack? Is it the pitbull / XL American Bully Owner or the German shepherd?