Let   $M$  be a compact, connected, orientable, irreducible 3-manifold with a torus boundary. It is known that if two Dehn fillings on
 $M$  be a compact, connected, orientable, irreducible 3-manifold with a torus boundary. It is known that if two Dehn fillings on   $M$  along the boundary produce a reducible manifold and a manifold containing a Klein bottle, then the distance between the filling slopes is at most three. This paper gives a remarkably short proof of this result.
 $M$  along the boundary produce a reducible manifold and a manifold containing a Klein bottle, then the distance between the filling slopes is at most three. This paper gives a remarkably short proof of this result.