Lies. If you had checked Death Recap, it would've clearly told you that you died to 206 magic damage from Dragon's Statikk Shiv.
[slayer-jinx-wink]
But in all seriousness, though, the state of damage in this game is kinda wack. There's too much damage overall, but on top of that there's also just too much damage that ignores defenses. I used to support target-agnostic damage as a means of equalizing damage against squishies and tanky targets, but failed to realize in the process that tanks and fighters are tanky for a reason, and that being able to just ignore one of their major strengths means they end up getting devalued, with little they can do against it. It creates this major balancing issue where tanky champions end up needing to be balanced around a vast portion of their defenses getting ignored completely, which then screws over whichever champions weren't updated to the newest true/max health damage craze. At this point, it might be better to not only turn back on this anti-tank damage inflation, but go even further and remove all true and max health damage from the game, with appropriate balancing given to tanky champions in the process.