"Maintenance of other peoples code is usually more difficult than understanding what you wrote yourself."

This is true. Often the types of things that folks look for though are nuances and style that come through with what someone writes. Do they have comments in their code? What standards are they following? Do they have test cases? How well do they handle exceptions? Etc.

The structure and accoutrement that comes along with code / work product can be quite telling.

The above being said I'd say what you did in the "best interview" was very appropriate as well. What I've generally seen out there is a "homework assignment" is often a one size fits all as an attempt to eliminate qualitative bias ...

I'm a lot more minamalist about comments, documentation, and unit tests with personal projects at home than I am at work. The stuff I work on at home are for my own enjoyment, and usually the projects are small enough and my time to work on them short enough that I don't put extra time making sure everything is ironclad. Good descriptive function and variable names and decent structure is about all you can expect with that code.