According to the official rulebook for the board game: "When a player completes his third quest card, each other player takes one more turn, after which the game ends."

I've been playing some games vs AI and sometimes this final turn does not happen. In my last game I would have won if I was able to take this final turn but after the AI claimed his main quest the game was simply over. But this does not seem to happen all the time as I've claimed my main quest and the AI still received a turn. If it matters, it was an AI game with only 1 quest, I was playing Triss and the AI was Yarpen. I believe I took the first turn which may have something to do with it (like the game is letting a "round" finish and that ends the game, instead of giving everyone one more turn. Since Yarpen went 2nd the "round" ended and so did the game).

EDIT: Version 1.0.2. I've got pretty slow internet at home so I haven't had a chance to update. Sorry if this has already been noted and fixed.

I've noticed that too..

I'm not sure but I might have spotted this too in hot seat mode. I was playing three quests goal with all four characters, and when Dandelion won game just ended. This was on 1.04

I think it depend on the place in the turn of the hero the complete all the quest.

For example if the hero is placed first in the turn then all other players get to play their last turn, but if he/she is in the end then the game is over.

It's exactly that, It's not that every Player gets 1 Turn after the Final Main Quest is finished, just every Player who didn't Played in that Round like

Player 2 end s the Game on Turn 19, Player 1 would not get another Turn since he already had his Turn 19, but Player 3+4 would get their 19 Turn since they just had 18 Turns, after realizing that I must say that it's even an pretty fair Solution :)

It seems that this is so. Dandelion has his turn last, so it fits.