(a) A prosecution for libel cannot be maintained against any person for the publication of a fair and true report of any judicial, legislative or other public and official proceedings or for any heading of the report which is a fair and true headnote of the statement published.
(b) Subsection (a) of this section does not apply to any libel contained in any other matter added by any person concerned in the publication; or in the report of anything said or done at the time and place of the public and official proceedings which was not a part thereof.