A piece of draw rock measuring 24"" by 12"" and 1-3"" in thickness fell hitting the canopy of the roof bolter. A piece of the rock measuring 8"" by 12"" and 3"" in thickness broke off the larger rock and struck the roof bolter pusher plate mounted on the drill boom, and then bounced back striking the employee in the nose resulting in a laceration requiring 12 sutures.