Not to put words in other people's mouth but I believe he is more concerned with 'version of Lisp' than the 'statically-typed' part. It is kind of like saying basic is an interpreted version of C. The two languages are more or less unrelated outside of the fact that both are impure functional programming languages.
I'm familiar with type inference, thanks. I have no idea what it has to do with Lisp.
I just interpreted the article an imprecise way of saying " they're both functional, but one is statically typed," by assuming Lisp as the canonical example of FP (rightly or not).