Thanks for the advice so far. I just want to clarify that I'm not upset that the players went another direction than the module supposed. And though the module does provide some guidelines about saying that the townwatch doesn't really get involved ... it's hard to justify that they would not come if people were reporting a murder in progress.
The lawful good cleric (who kind of started the attack) admitted to me after the session that he was getting bored, so that kind of explains things. We've had several very heavy combat sessions in a row, so I told them that we'd shift a little to something more investigative for that session.
The logical consequences for their actions, would seem arrest, imprisonment, trial, and execution (for those who actually attacked to kill; the second cleric, who merely supported the combat by healing her injured comrades, would likely be imprisoned for a long time for being an accomplice). Their investigations around town would suggest premeditation for the crime.
I'm just concerned about punishing the players too severely. This would be about the equivalent of a TPK to arrest and imprison/execute 4 party members. The sorcerer is doing his own thing in the temple, and the paladin and fighter are working as informants for the town guard. Even if the 4 party members break out of jail or evade arrest, it's unlikely the other three will join them.
The lesson I've learned? All dungeon crawls against obvious evils from now on!
Retreater