You are now hitting at the core of the issue, to most developers bugs, bad code, correct API's matter, you are asking them to look past something that is engrained in their work ethic, personality, and quality as a developer to measure their worth as a developer. It does not matter what the filter truly is, their is a perception on the developers part of what they are being tested for, because they attribute what makes them of value to the test. As such the correct solution is what makes them valuable. You can't tell them to give you what they perceive to be the incorrect solution and expect it to accurately reflect what they value in themselves as a developer, that the interviewers bias. The fact that the filter is being misinterpreted is irrelevant or very relevant depending on your perspective. To the interviewee, they are going to perceive the task just as many on HN have and no amount of prodding to give up their nature is going to make them perform well, conversely they are going to perform worse. I have neglected the fact that the filter is being misunderstood for the very fact that, it will be misunderstood and for that alone it sets people up to fail.
This is one of the point that I am getting at, you are right it's not just the code that is being judged, candidates know that too, so when they are standing at the whiteboard a million things about being judge may be going through their mind. It has nothing to do with being stodgy or honorable or above the effort and everything to do, with some people just cannot perform in such an environment. People hold out that it is a negative filter, that if you can't pass it, you are a definite negative and observations on a lot of peoples parts are not confirming that assumption. I side with the author of the article that there is an all inclusive way to identify good candidates that fall into this category as well as candidates that would pass the whiteboard test without resorting to the whiteboard. I am not arguing that people should not be able to code, rather I side with the author that there is a better way to identify the people that can and receive more positive hits in the process. Thus reducing the interviewing cycle and identify more talent in a constrained market.
I have yet to see someone who says that they would not pass the filter. Every single example I've seen in this thread is someone making up a different filter and saying that they would not pass that. I see people saying that they took a long time to debug subtle bugs in it, that they don't know the definition of the problem, or that in general they need documentation to code, all of which is completely irrelevant to the filter as given. Subtle bugs are allowed, the definition is given to you, the solution doesn't need any documentation (and if it does, you can just make up whatever API call you expect would be present in a sane standard library)
I'd be shocked to find any good programmer who, given the definition of Pascal's triangle, couldn't produce some decent, possibly buggy, incomplete, and syntactically incorrect, code on a whiteboard to print out a row from it.
I've yet to see anyone give an argument for how a good programmer could fail this test that doesn't rest on some feature of the test that doesn't actually exist.