Employee was installing ground control mats when the jackleg drill jumped forward, pinching his left hand ring finger with the machine, causing a fracture to the tip of the finger and a laceration which required sutures. (misc mail 5/30/08 #4-He had complaication with the finger & dr. took him off work on 5/22. he received a full release on 5/27/08 after missing 3 days work)