No person and no governmental or recognized nonprofit health or welfare organization or agency shall be held civilly or criminally liable for any diagnosis, opinion, report or any thing done pursuant to the provisions of this act if he acted in good faith and not falsely, corruptly, maliciously or without reasonable cause; provided, however, that causes of action based upon gross negligence or incompetence shall not be affected by the immunities granted by this section.
50 P.S. § 4603