They also employ what I call the "slow drip"...

An aircraft is out of position, so the flight is definitely going to be cancelled, but instead of cancelling the flight, every 10 minutes, they'll announce a further 10 minute delay to the flight.

If you get frustrated and leave before its officially cancelled, there's no compensation to pay.

The moment it hits 3 hours, and compensation will have to be paid, the flight is suddenly cancelled.