In an opinion more remarkable for its castigating tone than for the question of law it settled, state Supreme Court Chief Justice Ronald D. Castille last week delivered a broadside to fellow Justice Joan Orie Melvin, questioning her logic, her understanding of constitutional law and accusing her of “the height of judicial activism” during her first month on the bench.

Whether it’s a one-time warning shot or a signal of friction to come is anyone’s guess.

“I haven’t seen anything quite like this in a Supreme Court opinion in Pennsylvania in a long, long time,” said Robert Byer, former Commonwealth Court judge and head of the appellate practice at Philadelphia-based Duane Morris.