nice one boss laitzu... as of current basic life support and first aid guidelines, primary first aiders (those present at a scene of an accident), are not obliged to perform the rescue breaths when doing CPR. First aiders may choose if they will or will not give rescue breaths to the person being resuscitated, unless they have adequate personal protective apparatus on their person.
chest compressions are given until the medical response team/ emergency services arrive and take over.