Very wet and misty day with polished granite so poor combination from the start. Made the first couple of moves and then place a small nut that appeared good. Moving up and left of the gear placement on smeary foot holds both feed let go and slid down the rock. Belayer took and the the climber landed on the gear which popped out of the placement. Climber then fell to the ground, partly spotted by belayer, landing awkwardly on left leg.