pph help

I was eating at a restaurant this afternoon. I heard a lot of commotion, and I realized that a gentleman had collapsed. I know cpr, so I rushed to his aid. I used the new adult cpr instructions to save him. Another man kept yelling that I was doing it all wrong. I had swept the airway, only to find that the man had not collapsed due to choking. He was in cardiac arrest. He was not drowning, and I did not suspect an overdose, so I began to use chest compressions only, which is now the guideline for adult cpr. It was apparent that the other gentleman did not know that new cpr guidelines have been implemented. If I had used chest compressions and breaths, I may not have been successful in saving the man's life.