Allied minions attacked our Kassadin.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1635871103/43560953

Our Kassadin was top lane against their Kha'zix. I wasn't watching, but Kass later described it to me that he was fighting the Kha'zix at level one, and when he moved behind his minions, they turned and started to attack him, causing him to die. Kass noted the event in the in-game chat and Kha'zix acknowledged that it had happened.

And that's all I really know.