Unfortunately, he neglected to mention exactly what he meant by "documentation", so his hand-wavey arguments can basically mean whatever you want them to mean, and any dissenting argument can easily be dismissed and diffused like the mountain of sand we're standing on.

Always document your code in a way that you feel the person replacing you some day can come back to and quickly get up to speed on why and how things work. Reclaim your future time by putting a little more effort into the present.