Difference between pointer-to-pointer vs reference-to-pointer (C++)

Question

I have a bit of COM code that uses interface pointers. The original author of the code implemented functions that return an interface pointer like this:

HRESULT Query ( IN BSTR sQuery, OUT IEnumWbemClassObject* &pEnumerator ); // (1)

instead of the traditional

HRESULT Query ( IN BSTR sQuery, OUT IEnumWbemClassObject** ppEnumerator ); // (2)

The function (1) is called like this:

hRes = Query ( sQuery, pEnumerator ); // (3)

which definitely looks wrong but it works fine. I'm not sure if I'm just picking up this line because the out parameter is not a pointer to the output variable or because there's something wrong with this approach.

Is there an advantage to using a reference-to-pointer instead of a pointer-to-pointer for out parameters?