The top upvoted answer to the question, Three notes on the violin? is actually in-correct. In fact, a lot of the ideas tossed around on this question are mis-informed. I of course mean no offense, and I deeply respect all of the people who make this site possible.
And obviously, these people are totally genius. You don't get tons of reputation on this site by faking it.
However, the question was about a specific technique on a specific instrument, and in some cases, as demonstrated, a knowledge of other instruments is not enough to answer questions about technique on other instruments.
So, on questions tagged as "technique," should users need some degree of expertise in that instrument to answer? Kind of like protected questions, but more specific.