(a) Party asserting immunity.--If a cause of action based on protected public expression is commenced against a party, all of the following apply:
(1) If the party is immune under section 8340.15 (relating to grant of immunity), the court shall award the party attorney fees, court costs and expenses of litigation jointly and severally against each adverse party that asserted the cause of action.
(2) If the party asserts protected public expression immunity and the opposing party voluntarily discontinues the action under Pa.R.C.P. No. 230 (relating to voluntary nonsuit), with or without prejudice, the court shall award the asserting party attorney fees, court costs and expenses of litigation jointly and severally against each adverse party that asserted the cause of action.
(b) Party opposing immunity.--If the court determines that a party's assertion of protected public expression immunity is frivolous or filed solely with intent to delay the proceeding, the court shall award the opposing party attorney fees, court costs and expenses of litigation, incurred in opposing the assertion of protected public expression immunity.