Killing someone as Jhin while they are in fog of war might dc everyone on the other team

I was playing Jhin today and yesterday, and everyone on the enemy team dc'd at once, I do not remember what happened when it happened yesterday, but in the game I just played I killed Kayle with my W while she was in fog of war. I had yomuus and celerity boots at the time. My rune page was S1221 P031.