On September 21, 1987, Bart the Bear struck director Jean-Jacques Annaud. During a pause in the filming of The Bear, the Director thought a photo shoot would be a good thing to do. He invaded Bart's "territory" (his enclosure) without Bart's trainers' permission, or Barts, thinking Bart was comfortable enough with him to allow it. Annaud made a sudden move with his camera, pointing its lens at Bart, who perceived it as a threat and gave him a powerful smack with his right paw, then jumped on him (though Bart slid off, as it was on a hill's slope.)
Fortunately, the trainers were able to call Bart off quickly, as the director was playing dead hoping to survive.
Other than the blow, Bart only put a single puncture into the director's hindside, which required cleansing and attention for 2 months following.