How so?

return affects control flow, which a function in general cannot (leaving Coro aside). Execution after a function returns will always resume right after where the function was called.

The only built-in function that somewhat affects control flow is exit.

There are also goto, next, last.

In the context of the vague assertion I was replying to there is no difference in my opinion. When 'return' is called it does it's job just as when 'open' is called. The difference the OP doesn't seem to grasp is that when return is called, anything after it in that block doesn't execute (how could it?) This is by design and is how other languages work.