From what Merlin could tell, the rewards he received for finishing the quest was a small amount of experience and the four vials of holy water. He was satisfied with the rewards, it wasn't that important of a quest. He wasn't yet sure of the consequences that completing the quest would bring in the long run, so ultimately he wasn't pleased with his current situation.
Sir Redmond was a corrupt noble, and he most likely had connections with other corrupt nobles. Merlin couldn't know for sure how many factions had some form of connection with the man, or what kind of power vacuum his death would have created.
Due to his quest not giving him a strict warning about consequences in the town, like his quest to assassinate Arwell Lychester did, he wasn't completely worried of extreme changes. But this didn't mean that his death wouldn't cause changes, just that they weren't considered important enough by the system to be mentioned.
