[slurgfest]

If you want to gauge ability to communicate then you should probably find some way to get relevant work samples, like explaining the kind of thing which will have to explained in the job (e.g.: docs or brief presentation on something), rather than relying on the totally unreliable assumption that asking someone bad things about themselves in a high-pressure situation is a close analogue to what they will be doing on a daily basis.

This is like the ancient Chinese exams which assessed applicants' suitability by their knowledge of classical poetry. Of course people who are very well prepared or smart will do better in aggregate and with certain biases, but this doesn't mean you are measuring what you claim to measure.