Baron 30,000 true damage instant kill

On my recent ranked Braum game I was jumping to an ally near an aggro'd Baron and then my ally Zhonyad Baron did it's attack where it starts shooting closely and then starts shooting outward slowly and it hit me once for 30,000 true damage and insta killed me I was executed by baron if you can check back in the game and look at it, not sure if you can I didn't get to record it but it was spectacular I don't think Baron is supposed to do that (hopefully) Hope you can fix!