Killing my teammate

Right before the 16 minute mark there was a team fight that broke out. I was doing my thing as jinx, firing my gun like a madman. Then I got a quadrakill. I looked at my score though and it showed me only having 3 kills. Even in the match history it shows that I got the largest multi kill with 4, despite having only 4 kills in the game. Turns out I killed our kallista in the midst of the fighting. I don't know if anybody can shed some light on what happened.