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 ...