Also, Common Lisp (CLOS, in particular) supports multimethods (defmethod), contrary to what the author claims. And all of the special forms I saw in clojure have a counterpart in common lisp.
In fact, a lot of common lisp implementations (I like SBCL) have support for threading/asynchronous action built in. The one problem is that none of that is part of the ansi spec, so most multithreaded code won't be portable between implementations.
It isn't the language's fault that your teacher wouldn't let you use all these features.