There usually are two people doing things that are wrong when a collision happens. So, the fault isn't entirely the OP's, but saying that the accident would be avoidable if the other guy was better at defensive walking/riding/driving is specious. A person should always ride/drive as if there is an unknown object directly in his path that he can't yet see; i.e. don't overrun your sight path, it's too fast. Whose fault would it be if there were a tree down across the MUP at the same location, the tree's?