Unfortunately, I don't have a savegame before that moment. Since Locke's quest isn't vital, I moved on with the game and replaced all my saves since then.
Still, I could try to launch a newgame and check if it happens again, as this is fairly soon in the game. I'll see if I can do it this evening.
If I remember correctly what I did back then, it might be possible that I exited the Black Boar before Locke was set in his place, because as a veteran from Ego Draconis, I have the habit to exit the inn as soon as the soldiers leave, in order to make David spawn
