Lux ultimate doesn't deal damage sometimes

https://www.youtube.com/watch?v=HV9Kk97B9k8&feature=youtu.be

The ult's hitbox clearly hit him even when he moved a bit to the left because the hitbox is rather wide. In game, on my screen he was a 100% hit, i don't know what happened here.

Could be funky broken hitboxes.. could be anything I've had it happening to me being the victim once and i was like - "how am i not dead?"

in game that hecarim said it clearly hit him but he didn't die