Apparently, Carl was unaware of it as well despite the post and subsequent discussion receiving a fair amount of attention on HN at different times.
Disclaimer: I wrote it.
Lets assume that doing and telling increase luck surface area. We know, through observation, that both good and bad luck exist. Thus, there should exist situations in which telling and/or doing increase bad luck surface area.
All things being equal, the direction in which ones luck surface area will grow (good/bad) when telling/doing, is evenly distributed. In other words, you have even odds of good and bad luck when you tell/do.
Now, lets follow the general social studies assumption that people are risk averse.
You get a more tightly packed theory, albeit, less inspirational - the winning strategy in life is doing nothing and shutting up. :)
Now back to work.