[jerf]

Yes, I said that. Please try less hard for the "gotchas". There's no ambiguity here, the Go type system does not permit it; something is either a struct or a closure (or exactly one of the other valid types; even "interfaces" are actually a specific type in Go), and the linked code returns a struct. (Python, for instance, can create something that acts as both object and closure at the same time with an object that implements the __call__ magic method.)