Truth to be told, if quest log was made to be dynamic (which I think it was originally planned, then dropped from the game), then issues like this would not happen.
For example, any kind of checkpoint in the quest would update quota log and give feedback to the player that they did something that advanced the quest.
Game does cheat this in, couple of times, by completing the quest and adding a new quest, but most of the time player is left clueless regarding quest progress.