How to Handle a Tough Deposition Question

A former student sent me a link to this deposition video. I have no idea who the party is or what the dispute was about. In any case, it starts out pretty boring, but you must watch it all the way to the end, where it becomes one of the all-time great answers to a deposition question (and an answer that I have more than once wanted to give at one of my expert witness depositions):