The return email said that my test "has been thoroughly reviewed, but they don't believe they have a position available for me". After pressing the HR contact for feedback, I received a statement saying my code "was okay, clear and commented, however, there were some holes". I couldn't elicit anything beyond that. Reaching out through the grapevine, I learned that they failed me for my code crashing when it was fed malformed data. They intentionally do not tell the candidate about testing it this way. Draw your own conclusions from it.