http://www.martialtalk.com/forum/member.php?u=17859
Having Brown belts teach is one sign of a McDojang.
Again, it depends on the school and how long does it take to get to Black Belt. I don't know about the U.S., but here in our neck of woods many instructors don't hold black belts, and what is more interesting - this is typical for hardcore styles like Kyokushinkai, Brazilian Jiu-Jitsu or Kickboxing. In TKD, the minimal requirement to pass the instructor course in Poland is red belt (2nd or 1st Gup) which is an equivalent to brown belt in different styles. The trick is, those wearing the belt sometimes have 10+ years of experience. The highest graded active Kickboxing instructor in Poland is 4th Dan and he was a world champion 20+ years ago.
As a sidenote, all Kickboxing instructors in my club are brown belts, including myself. I don't think that we qualify for McDojang title, however.