Nunus Ult does 0 damage after dying while channeling!

Hey!

SO I dont know if anyone else has had this problem, but i have noticed it on ARAM and Summoners Rift, where if I am killed while channeling Nunus ultimate it does 0 damage. I always thought that Nunus ult did damage based on X amount of time it was channeled? The most recent time i noticed it was on ARAM when the entire enemy team snowballed right onto my poor Nunu Bot body, so i channeled my ult in a final "if i'm going down i'm taking you with me". At this point i had as well as other magic pen/ap items, approx 1170 dmg at max channel on ult. Most of the team decided to try to run, but a brave Ezreal stayed and Melee'd me to death, causing a big snowplosion, but no damage??? GG

Maybe a bug?