To paint an accurate sequence of events here, when initially asked to configure the torpedo and head for the nearest Maquis colony this still plays out as shown with the crew shocked, but still going along with it most likely holding onto the idea that it's part of some kind of strategic bluff by Sisko and he wouldn't actually carry through with it. But upon arriving at the planet when actually ordered to launch the torpedoes, hesitating the first time and then being directly ordered a second time Worf refuses, turning the safeties back on and declaring while he respects the Captain and understands his need to pursue the man who betrayed and dishonored him that this was *NOT* an honorable course of action and as a Starfleet Officer and a Klingon it was an order he could not follow.