Heat the oil in a large skillet over medium-high heat. Add the crab legs and cook for 2 minutes. Add the scallions, parsley, red pepper flakes, and wine and cook until the wine has reduced by 1/3, about 6 to 8 minutes. Add the lemon and lime juices and cook for another 2 minutes. Stir in the butter, 1 tablespoon at a time, to thicken the sauce. Taste and adjust the seasoning with salt and pepper. Serve immediately.