It's always cool to see a champ using an ability, but seeing all 4 animations of Kai'sa's autos on top of her q, possibly a w somewhere, and acrobatics made me swoon.
If you look at his gun in the final frame as he's bowing, it has the fourth shot loaded.
Go watch the cinematic again. At 2:22, Jhin pulls Whisper and it has 4 marks on it. At 3:07, you can see the gun has one round left. /u/Divine-Storm said it better when the cinematic came out.
There are times where I think I have good attention to detail, and then there are times where I read Reddit.