Ashe w/ Runaans -vs- Rammus Defensive Ball Curl

So I was playing ashe adc against a team with a rammus. All was well untill a teamfight broke out where i was autoing (with flurry up) a garen with runaans' bolts flying towards rammus (with defensive ball curl up). I died near-instantly due to the runaans's bolts with flurry activated procing rammus' returned damage (with defensive ball curl) around 4-5 times/sec (checked death recap: 900+ dmg from def ball curl, 500ish from abilites with no icons...). Has anyone else had this experience or is this just a bug?