I'm going to guess it had something to do with what happened in the top of the inning. With one out, the Crabs went home run-triple-single before Tyler Bortnick was hit by a pitch.
UPDATE: They added a couple more in the ninth inning when Anthony Scelfo was plunked. Palm Beach manager Luis Aguayo and pitcher Brett Zawacki hit the showers early.
UPDATE: From Charlotte's release (my underlining) ...
Both benches cleared in the seventh inning when Charlotte starter Alex Colome threw behind Palm Beach catcher Juan Castillo. That prompted Castillo to charge the mound and throw his bat at Colome, leading both benches and bullpens to empty. Stone Crabs catcher Mark Thomas tackled and subdued Castillo while order was restored.