[Gameplay] Nautilus W Cleansed Thresh Q

I only had this happen once so far, but in game I activated Titan's Wrath the moment Death Sentence was about to hit, just to have my shield up before the stun. As the hook landed it instantly cleansed (the particles even changed to the normal cleansed hook lighter blue). I did not have mikaels, qss, or the cleanse summoner (nor did anyone on my team). I was stunned for only a moment rather than the normal 1.5s and could not be dragged.

I don't know if this could be replicated, and don't really have the time to try.