You can always return a structure that contains both the boolean, lets call it isArrayValid, and the array... thus, after the function returns, you can test if the array content is valid and can be used.
Still, I'd recommend passing the array as an "out" parameter (ByRef) for the function... which returns the status as a boolean, or even an error code, which enables the caller to find out what went wrong when the array content isn't valid.