The Laws of the Game were changed last year regarding the DGSO and the wording made clearer.

Where a player commits an offence against an opponent which denies an opponent an obvious goal-scoring opportunity and the referee awards a penalty kick, the offender is cautioned if the offence was an attempt to play the ball; in all other circumstances (e.g. holding, pulling, pushing, no possibility to play the ball etc.) the offending player must be sent off. 

Click here to see the video in which the referee eventually makes the correct decision