In a large bowl, combine pears and lemon juice. In another bowl, combine 1/2 cup sugar, tapioca, cinnamon, salt and nutmeg. Add to pears; stir gently. Let stand for 15 minutes. , Pour into pastry shell. In a small bowl, combine the oats, flour and remaining sugar. Cut in butter until crumbly. Sprinkle over pears. Bake at 400° for 45 minutes., Meanwhile, in a saucepan over low heat, melt caramels with milk. Stir until smooth; add pecans. Drizzle over pie. Bake 8-10 minutes longer or until crust is golden brown and filling is bubbly. Cool on a wire rack.