HBP and Felix Felicis

During Slughorn's first lesson, when he offers the Felix Felicis to whoever brews a perfect Draught of Living Death. He warns the class that only one student has actually ever managed to claim the prize.

I would think that meant Snape? Slughorn taught Lily, so it fits that he was also Snape's Potions Master. And it's because of Harry having Snape's book that he managed to win it in HBP. And if it was Snape, what do you think he did with his vial of Liquid Luck?