if we don't place a perfect bullet that nearly instantaneously kills the animal did we just act unethically? but it wasn't intentional. but you did pull the trigger, that was extremely intentional. but i didn't mean to hit it there! but you pulled the trigger, and maybe you should've practiced more. so was it intentional? was it unethical?
these things happen way more with bows, way more with muzzleloaders. is the higher propensity of suffering thereby unethical in these methods of take? some may argue yes and perhaps have a point
overall, i think there are many practices in hunting that are far more worrisome as far as ethics are concerned.