Mike Dean was correct in awarding a re-take of the free kick between QPR & Manchester City. The following are 2 extracts from the FIFA Laws of the Game 2014/15 Rule 13 “Free Kicks”.
This indicates that the ref was correct to deny the goal by Charlie Austin as Joe Hart kicking the ball twice is an infringement. However, that is not all, Mike Dean was also correct in awarding a retake of the free kick, rather than an indirect free kick as indicating above.
The key reason being that Joe Hart’s first touch had not put the ball ‘in play’: