Fiora double vitals passive bug

Not sure if it was just a visual bug or a gameplay bug, but last game I was Fiora top against a Lux. Lux left vision with an East Vital open and then when she came back, both North and West PASSIVE(not ULT) vitals were showing. I didn't go in on it, so I don't know if there was a chance to proc both or not, or even if I was just being given double the chance of hitting a vital.