*BUG* Yorick 600K+ dmg in a game

I just finished a game. I was looking at the Game summary, and according to it the other teams Yorick did 600K+ dmg. I don't know if this is a bug in the mathematics of the summary, or if there is a bug with Yorick in game. It was the same on the client match history statistics report, and the online Match History statistics report. I have included the link below. Please look at the report. What's worse is that 500k of the damage appears to be true damage. I don't feel like this is possible, as he wasn't an all out slaughtering machine (with those stats I feel like he would've been 1-shotting the entire team) but something is wrong. He doesn't even have any skills/spells/items that granted true damage. Please look into this.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2152819064/35045119?tab=stats

Thanks -Path

I've also included the saved page.