Cameras can lie very easily with selective editing.
I really doubt the driver thought he actually hurt the dog when it happened.
9 times out of 10 that dog would have been ok? But unfortunately this time the diad board caught the dogs eye and this was the time the dog got hurt. The dog ran away and the eye swelled up.
I am not trying to beat up on the driver because the whole thing happened fast and the tiny fast dog took him by surprise.
Both parties have come to an agreement and life goes on.