Quote: "Someone whose name mustn't be mentioned will know the precise answer. "
Voldemort?
It's a side-effect of DBPro's array design, and has been deemed 'good'.
Individual array subscripts are used to calculate the offset into the array only - they aren't individually tested to see if they are in range (bounds checking is carried out on the calculated offset though) and there are no checks to see if the right number of subscripts have been provided.
... and yes, it is slightly faster - For each additional subscript following the first, there's also an additional multiply & add IIRC