WHILE LOOKING FOR A LEAK IN A HYDRAULIC HOSE ON A ROOF BOLTER, INDIVIDUAL WAS HOLDING HOSE BY DAMAGED AREA. THE HOSE WAS PRESSURIZED FOR IDENTIFICATION AND A SMALL AMOUNT OF HYDRAULIC OIL WAS INJECTED INTO TIP OF RIGHT INDEX FINGER REQUIRING THE FINGER TIP TO BE LANCED TO ALLOW THE OIL TO DRAIN.