12   When does a liability for duty arise?

(1)  A liability for duty charged by this Chapter arises when a transfer of dutiable property occurs.

(2)  However, if a transfer of dutiable property is effected by a written instrument, liability for duty charged by this Chapter arises when the instrument is first executed.

(3)  A liability for duty in respect of a dutiable transaction that is charged with duty as if it were a transfer of dutiable property arises even if the dutiable property is not in existence at the time that the transfer is taken to have occurred, or the instrument effecting the transfer is first executed, as the case requires.