[randomdata]

> It's ridiculous to expect an extensive spare-time open source effort plus 2-10 hours of free work for an interview.

It's a bit of a misnomer to think that businesses expect (or require, as some put it). In reality, they can only weigh their options. Of course, the more options they have, the more particular they can be. It is not unreasonable to think that they had many suitable candidates, and the one who had the most visible evidence of past work became the preferred choice of the group.

Mentioning to the OP what helped cinched the deal for what candidate did get the job may have just been meant as a point of information. Of course, it's difficult to say what really happened without being an observer to the events that took place.