Statements made by a lawyer in defense of his client fall under the immunity of the plea and the right of defence, even if these were formulated outside the legal procedure.
The Criminal Code provides that a lawyer enjoys relative criminal immunity ('the immunity from the plea') for “words spoken in court or writings submitted to the court” when they “relate to the case or to the parties”” (Section 452, paragraph 1 DCC).
Statements about persons who are/were not a party to the case also fall under this immunity, insofar as the statements are in the interest of the defense of the client(s).
The freedom of expression of a lawyer in the exercise of his profession is fundamental. According to the European Court of Human Rights, a lawyer enjoys a particularly high level of protection of the freedom of expression, for example when criticism in connection with a legal procedure is expressed via the media.
An interesting interpretation of the aforementioned principles following a recent decision by the criminal court in Ghent can be found in the contribution of professor emeritus Dirk Voorhoof in the Juristenkrant (“Judge safeguards immunity from pleading by lawyer Van Steenbrugge”, in Lawyer's newspaper 2020, ep. 418, 1 and 7).