is irelias e bugged?

I was just in a game against an irelia as pantheon. About three times in that game i was at a lower health percentage and she hit her stun on me. We were both full and she used botrk passive on me q'd and then stunned me. I was about 300 healh from full and she was full health. She proceeded to do this about 3 other times in the game and im just confused. The ability specifies same or less health percentage and she had a higher percentage.