To me it just look like someone wrote "unserialize" in their program without thinking very hard about the implications. There was nothing wrong with the first version.
Perhaps the deeper design and methodology problem was that the contract of that part which was re-implemented wasn't documented and tested well. Booooring.
I think that it's probably more entertaining for a noob audience (or any audience really) to peek into the funny things that tend to happen when someone uses serialization without utmost care. Especially in an interpreted or very dynamic language. Of course for that presentation to work you need to explain a little bit of technical stuff, but such is the price of an awake audience.