I am confused as to the last part of the presentation where you used category.TypeOf(DiggModule) and make a reference you say shouldn't really be made? Demos and training can sometimes be difficult for people who are really trying to make their code better and more flexible by using Dependency Injection and Inversion of Control, etc. However, then you will see things in demos which completely contradict what you have learned. Just once, I would like to read an article or see a demo where no compromises are made so I can really see what it's like to follow all of these practices.
I understand that sometimes these things are done for various reasons and mean no criticism of your demo. I just want you to know that for people who are not yet familiar with everything yet, it can be frustrating and confusing since you never get to see an example that is in complete agreement with what is being taught.