thedungeondelver
Adventurer
Sense motive only lets you read somebody's mind if you can manage a 100. Otherwise you'd just know the king wasn't being entirely truthful. But the wonder of argumentum ad baculum (argument by big stick) is that even if you call the bluff you still get baculumed.
Alternately, if the king was using Bluff (badly) to try and "code talk" to inform his court scribe about your eventual grisly fate while he was giving you your marching orders, you could pick that up with Sense Motive. But isn't that the sort of brazen Evil Overlord move the heroes are supposed to pick up on?
Though I do agree that player agency is a real problem with 3E, if only because as a DM you either bust your hump trying to model all the things players could wind up doing or try and ad hoc a ton of player requests. I appreciate the quick and easy ad hoc guidelines in 4E, even as it backpedals away from trying to simulate anything out of the PC's little bubble with furious speed.
Sense Motive - newspeak for KILL THIS RULE WITH FIRE. KILL IT. MAKE IT SO IT CAN'T HURT ANYONE EVER AGAIN!