That's just another way of sideslipping, was quite common when I flew gliders some 30 years ago (called slip-turn in english if I'm not mistaken). If you have sufficient speed (he obviously had, and I guess he had an airspeed indicator in front of him to make sure) that's a perfectly safe maneuver.
Enter "Bob Hoover" as search string into YouTube and see, how much abuse an aeroplane can take during a deadstick landing without stalling and spinning
