"we ended up hiring the candidate with the smoothest answers"
I mentioned this in another thread, but the point of coding questions is to see how they think about code, whether they understand how to walk through it (have a machine model), if they can pick out and evaluate edge cases, and how they can work with hints from you on how to improve their answer. Hiring based on ability to answer a particular problem is probably only a slightly better indicator of ultimate job success than height.
I mentioned this in another thread, but the point of coding questions is to see how they think about code, whether they understand how to walk through it (have a machine model), if they can pick out and evaluate edge cases, and how they can work with hints from you on how to improve their answer. Hiring based on ability to answer a particular problem is probably only a slightly better indicator of ultimate job success than height.