No one says that the design had to be perfect or that even if it started out “perfect” that it had to remain that way. Some critics will point out what they perceive as faulty body parts, that a real intelligent designer would have designed something better. But in the real world we see design compromises all the time and we also see design mess ups. History is littered with intelligently designed things that didn’t work and/ or were dubbed “engineering blunders”. So what? That is why we use the term intelligent design.