It really shows that he doesn't have any problems finding the proper level of aggression postflop. And it also shows the power of preflop hand selection as it is clear from the actual hands that you get into trouble by 3-betting with hands like QTo. It illustrates the common "paradox" that in limit hold'em preflop play is very very important to your expectation but on the other hand, it's "postflop where the money is made".
I think it was clear from the beginning that DD shouldn't have much trouble coaching a player like this and it will be interesting to see how soon he will be a decent-to-great player.
I'm also somewhat curious to hear the reasons of this project. There's nothing wrong or bad to learn limit hold'em, but it's still somewhat odd as most people claim that no-limit games are better on average. Or is it just the case that one needs more opportunities for playing in the high stakes in addition to your normal tables or something?