In any case the court on motion of the prosecuting attorney may order that a witness shall not be excused from giving testimony or producing any papers, documents or things, on the ground that such testimony may tend to incriminate or subject the witness to a penalty or forfeiture; but the witness shall not be prosecuted or subjected to criminal penalty or forfeiture for or on account of any transaction, matter, or fact concerning which the witness has been ordered to testify pursuant to this rule. The witness may nevertheless be prosecuted for failing to comply with the order to answer, or for perjury or the giving of false evidence.