What is the force of the can here?
Do you mean "in accordance with the rules and procedures of play"? Then what you say is not true for the particular episode of play being discussed, where the players' victory precludes the GM simply going on to narrate the advisor improving his standing vis-a-vis the baron.
If the point is that, in [MENTION=23751]Maxperson[/MENTION]'s game, the same is not true - because Maxperson plays with different rules and procedures - well, yes, that is self-evident (or nearly so).
But as I posted upthread, this does not tell us about any difference in the role played by NPCs in these games. In both approaches, NPCs provide opposition/antagonism. Rather, it tells us something about differences in who enjoys what sort of power to change the content of the shared fiction.
I believe that [MENTION=957]BryonD[/MENTION] and [MENTION=23751]Maxperson[/MENTION] disagree with the previous paragraph (or, at least, with its first and second sentences). But they haven't stated what the details of that disagreement.
Better. I actually addressed this division in the post where you first responded with ' but NPCs aren't real'. It was the discussion about whether or not NPCs exist only to frame and oppose PC actions, or if they exist and PCs can pit themselves against them if they choose. I get that you're missing the distinction here, and, to be fair, it's somewhat subtle. In the former, which appears to be how you play, NPCs have no point except to act as foils to PC actions -- they only have enough form and substance to provide suitable obstacles (or perhaps allies) to PC intent. They do nothing except act in reactions to the PCs. An NPC in this model will never have it's own agenda that it pursues absent PC involvement -- any such agenda will only exist in the event that it's needed to oppose PC intent in a challenge. You've indicated as much with statements about keeping NPCs vague so that future changes to them due to player declarations and need to challenge them are coherent.
The latter concept, though, involves NPCs that are created as if they have PC level interests, motivations, and agendas. In this version, the NPCs are acting on the world independent of the PCs, and this may be the source of conflict. This is the proposed version Max is using, the NPC as alt-PC, not merely as foil to PCs.
To bring this analysis to bear on your play example, in your version the advisor only has merit as a foil to the PCs. He was framed as a challenge, and then the challenge was enacted, but the advisor is entirely bound to the results of the challenge. He only has an agenda in so much as it exists as a challenge to the players. In this model, it's right and proper that the advisor cannot engage in mitigation, because the advisor was only a toll to challenge PC intent, and when the PCs succeeded in implementing their intent through the challenge, the advisor was defeated. The advisor cannot initiate a new challenge that alters this success, only the players can enact a new challenge that might alter this success. The advisor only ever reacts to the players.
In the other method, the advisor still has independant agendas, so the player success at the challenge is now a setback, but the advisor can now plan steps to overcome the setback and act upon them, even without the players engaging in a new contest that stakes their previous victory. In this, the advisor can force the players to react to his advances -- he can initiate a new challenge that may adjust the success of the previous one. This is because the advisor has his own agency in the game and isn't only reactionary to the players.
You would call the second method DM driven. I've used DM centric, largely because I believe the -driven categories are too binary. But, regardless of terminology, I think the primary distinction between DM and player driven is the reactionary status of the gameworld -- if the world only every reacts to the players, it's player driven. If it exists outside of the players, and acts without player input, then it's DM driven. I'm okay with this, with the clear caveat that nothing is fully one or the other -- it's a spectrum. My games are both -- the macro is DM driven, in that there's a plot ongoing that will continue without player involvement, and on the micro in that I break my arcs down into sandboxes that largely react to the players.