It was <PERSON>. Yes <PERSON>'s handbook provides a fool proof way of brewing the potion, but the way the 6th HP movie presents a specific scene makes me rethink that it was <PERSON>. The pineapple sweets. It was the scene where <PERSON> is recalling one of <PERSON>'s memories in the Pensieve. If we assume <PERSON> has taken liquid luck just prior to the meeting, the scene makes so much sense. The scene begins with <PERSON> asking <PERSON> if a certain professor will retire, <PERSON> is probably testing the effects of liquid luck and wanting to get confidential information from <PERSON>. <PERSON> replies, "well I couldn't tell you even if I knew could I?" Which indicates that providing the effects of liquid luck, to make all of your endeavours succeed as long as possible, <PERSON> did in fact not know this information, otherwise he would have shared it. 573
The next line is the killer of this theory really. Professor <PERSON> says, "By the way, thank you for the pineapple you are quite right it is my favourite...but how did you know?" to which <PERSON> mysteriously replies "...Intuition." In fact, <PERSON>'s use of liquid luck allowed him to correctly identify and purchase <PERSON>'s favourite sweets, probably in attempts to ease him up to share information about the hocruxes. As we learn later in the movie, he in fact reveals the truth about hocruxes to <PERSON>, thanks to <PERSON>'s use of liquid luck. What makes this theory especially disturbing is that <PERSON> massively regrets this memory, probably because he thinks he helped <PERSON> achieve power and spread evil and misery in the world when he told him about the hocruxes, not to mention killing one of his favourite students and <PERSON>'s mother, <PERSON>. But <PERSON> doesn't know that his defences were simply down due to the liquid luck he had awarded his student for properly brewing the potion known as Living Dead. Or perhaps in the back of his mind, he does know liquid luck was used against him and regrets having given it to <PERSON>. Evidence for this could be the way he fantasises about reacting angrily to <PERSON>'s request about the hocruxes. Probably how the true encounter would have gone about if not for <PERSON>'s use of liquid luck. 573