Yorick and Kha'zix damage Bug?

I'm like 99% sure they didn't do that much damage in the game. Is the stats reading wrong or was the damage glitched in game? (Game lasted 30 minutes)

(I found this https://gyazo.com/38c08ac937c3bfb151a8da7929e5afe2 at http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2150494735/38135740?tab=stats this shows reaching and outstanding damage of 547.3k in a 52:55 minute game and the stats say that 501.8k came from true damage)