Lolking messes up kill contribution stats or unapproved third party programmes?

Tonight I had a game in ranked mode solo que, in which my team lost. Later, i visited lolking to check my stats and i found out that all the players of the enemy team had too high kill contribution. One of them had 123%. I did the math and found out that their kill contribution was doubled.

I checked my other games and all kill contributions were fine. I checked all the other matches of the enemy team players and their stats were fine calculated too. Only 1 enemy player had messed up stats, the one that carried them actually. His kill contribution was in most cases twice the one it should be and sometimes it was lower (about 8% lower). Does anyone know why this happens? Are the maths same in lolking and lol? Is there a case that this player is using an in-game programme to make his kills look more and gain more gold during the battle - gaining an unfair advantage?

Excuse me for my bad english and my ignorance on these matters, thanks in advance.