Guillaume's Quest (Remove the Curse from Vivienne) (The Witcher 3: Wild Hunt)

Actually a question about this quest when participating in a tournament. It is necessary to remove the curse from Vivienne (who is slowly mutating into an oriole bird). With the passage of questions, no questions arose, Geralt took the egg from the nest and seemed to have removed the curse. But something seemed suspicious to me. There, when she bathed in the pond and said that water always helps, Geralt says "Interesting" and you can still stay at this location. Somehow I missed this moment. Are there alternative options for passing? And what if you tell Guillaume?