The fact that there are extensions to those languages to add static typing still doesn't establish much of a correlation between "knows this language" and "groks static typing." There are lots of very proficient Schemers who have never used Typed Racket.
Yes, my comment wasn't meant to be totally serious. If static typing extensions were really used by everyone using Racket and/or Erlang, I wouldn't even have had to link to the extensions to begin with :)
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