Some Clarity

In Tuesday's post I talked about the confusion with when a maul ends 'Al Italia' i.e. the oppo disengage and run away.
Its seem there now some direction from the IRB, the RFU (god bless 'em) asked this question..

The RFU has requested a ruling relating to Law 17
A maul is formed with Team A pushing their opponents (Team B) back towards their own goal line with the ball being clearly visible at the rear of the maul, all the defending side (Team B) bound to the maul voluntarily exit the maul, has the maul successfully concluded or is the maul still active?

And the answer from the IRB is

The maul has not successfully concluded and it is not still active.
As the players of the team not in possession have all left the maul the maul ceases to exist and has not ended successfully or unsuccessfully as determined by the definition of a maul. The maul has ceased to exist and the ball is now in open play and the relevant Laws apply.

So do I penalise, obstruction, do I let the oppo pop around the back? This Saturday, I'll shout and tell the ball carriers to use it and hope they take the hint.