It's a GM call, some combat maneuvers gives the AOO before the maneuver, others don't state it. If the hobgoblin moves to engage, the whip can still be used in melee, but I can hope that it misses.<br/><br/>If it doesn't get the AOO before the trip (it is my initiative, afterall), he can't close to do anything.<br/><br/>Anyway, whatever happens happens/