Baron 1 Shot kill on Braum

Bug Report: I do not believe my computer specs matter and my internet connection was working fine at this time. I was playing as braum on normal SUmmoner's Rift.

Steps:

1. My team had just started killing baron we all started at full health.
2. I take aggro after the first 2 shots from baron applied to our fiora.
3. After 2 or 3 shots I throw up my e move (The shield that blocks attacks.)
4. At this moment Baron used his knockback move and hit my shield. 5 . I was 1 shot insta-killed by Baron. I had about 2600 hp total and had lost around 400 leaving me in the neighborhood of 2200 HP. The announcer yells "EXECUTED" and the on screen graphic displays that Baron killed me. My death recap read that Baron did 422 damage to me total.

I believe this had something to do with the Braum shield interacting with the Baron knock back, however, I tried to replicate on our second Baron attempt of the game and could not get it to happen again. But I do not think I timed it right and I think I blocked an auto-attack.