The `err, result` function signature implies the function is an asynchronously executed node-style callback, which can never return anything anyway. Well, it can return something, but nothing internal reads it and there's no way for user code to access the returned value so return becomes only useful for short-circuiting.
When I saw that, I imagined myself spending 10 minutes trying to understand why he does that. But maybe I'm not familiar with a JS best practice here.