I don't understand the relationship here. F# is a strongly-typed hybrid (functional and imperative) language that is a thin skin around CLI. It is not a dynamically typed language and therefore is not the right tool when you need/want dynamic capabilities
(like Python and Ruby afford...). Dynamic languages are dynamic at the type system level. F# targets a static type system, which is baked into the CLR (this is why the DLR was invented...).
What do you mean, exactly? C
He's reflecting on the fact that F# has a dynamic feel to it due to its strong support for type-inference.