"When a private person gives to a prosecuting officer information that he believes to be true, and the officer in the exercise of his uncontrolled discretion initiates criminal proceedings based upon that information, the informer is not liable under the rule stated in this section even though the information proves to be false and his belief was one that a reasonable man would not entertain. The exercise of the officer's discretion makes the initiation of the prosecution his own and protects from liability the person whose information or accusation has led the officer to initiate the proceedings. If, however, the information is known by the giver to be false, an intelligent exercise of the officer's discretion becomes impossible, and a prosecution based upon it is procured by the person giving false information. In order to charge a private person with responsibility for the initiation of proceedings by a public official, it must therefore appear that his desire to have the proceedings initiated, expressed by direction, request or pressure of any kind, was the determining factor in the official's decision to commence the prosecution, or that the information furnished by him upon which the official acted was known to be false."