So I have had my suspicions about this for some time, where it appears the game is stopping the final board cascade when the counter hits 0.
The following happened today- I reached 0 moves, I paid for extra moves with 10 gold bars, then when the game resumed the board carried on cascading - without me making a single move - and guess what I didn't need any extra moves because the last dragon dropped.
Had the board completed cascading before cutting me off, I would have completed the level and saved my precious gold, which is SO hard to earn for free now.
So in my mind I'm clear this tactic has been confirmed - anyone else notice it?