Billy Wagner is listed at 5'11" but if I was in the box against him in his prime I'll bet he looked 6'5. Regardless of who's recording what, it is their business what they want to see and how to use that data. Your business is to out perform the others, simple as that. Anyone who relies on height and weight as a barometer will not have a job for long because as soon as their bosses see guys falling through the cracks because of those non-talent statistics, they will be gone.
As far as kids who give this "urban myth" any credibility, tell them to use it as a motivational tool to prove the skeptics wrong.