It's such a shame the man had to shoot the dog.  Labradors in general are decent dogs and not know to attack people for no reason.  He could have shot into the ground or into the air to scare the dog off.  I feel bad for the lady that lost her dog but this is why you keep your dogs on leashes.  If she hadn't let the dog off the leash this probably would not have happened.  It's a terrible and unfortunate situation all around and I hope I never find myself with the same problem.  I'm gonna go play with my dog now and be grateful.